After trying many variations I have found that Corki does exceedingly well with 2 basic items - everything else is pretty much up to player discretion whether you go Ability Power or Attack, although personally I find attack works the best, or some hybrid of attack and AP.
I am not going to get into runes or mastery - to each his own. This guide is a how to guide on itemizing and playing Corki to own in just about every game (for the record I go complete offensive mastery and I have no runes yet to play with).
Starting Summoner Skills:
Teleport
Heal
Starting item build:
Sapphire Crystal - 400g
(optional) Healing Potionx2 -35g each
Reason for starting items:
It is very easy to establish early lane dominance with Corki if you can harass well. Those moves are of course dependent upon your mana pool (243 base). Starting with the Sapphire Crystal gives you 443 mana at level 1.
Phosphorus Bomb - cost 70 mana at level 1 for 80 damage.
243 / 70 = 3 Phosphorus Bombs (240 damage in harassment)
443 / 70 = 6 Phosphorus Bombs (480 damage in harassment)
This does not account for mana regeneration or the mana you gain from leveling.
In short, at level 1 you have enough mana pool to nuke a champion back to the well. By using them often, it is typically enough to force the other champions away from the minions so that you can farm freely and keep the enemy from farming. Also, when you start using Valkyrie, you have enough mana to hit the minion wave, and drop a bomb when you land to either farm the minions quickly or to hit the enemy champion for more harassment.
Item plan:
The idea is to build Sheen as quickly as possible, even before boots. This will soon lead to having a Trinity Force as your first big item. After getting Sheen, I usually go Berserker Greaves for the move speed and attack speed, which works really well for hero ganking, then getting Phage (Ruby Crystal first, then Long Sword), then Zeal (Brawler's Gloves then Dagger), and finally finishing Trinity Force. With these two items you are a major force to be reckoned with early through mid game.
Reasoning for Sheen/Trinity Force first:
Sheen gives you an awesome burst combo early game. Your abilities proc Sheen often, and combining your attack with your spells make for a potent hero killing combination. Trinity Force gives you some really nice abilities for burst and chasing heroes. Yes, you do have Valkyrie, but having a slow makes a big difference between getting the kill quickly or chasing a hero halfway across the map and possibly running into their other teammates. The proc from Sheen gives you a nice burst when you Valkyrie in and start to unload (as I will describe in detail later) and the slow from Phage will make sure they won't be able to get away, with only few exceptions. The overall stats give you everything you could ask for offensively - hp, mana, damage, AP, attack speed, and move speed. After your initial strike, using your rockets in battle will continue to proc sheen for sustained burst.
Item path - in order:
1) Sapphire Crystal +200 mana (start) - 400g
2) Amplifying Tome +20 Ability Power - 435g
3) Sheen (combine Sapphire Crystal and Amplifying Tome) +250 mana and 25 AP - 425g
4) Boots of Speed +1 Enhance Move Speed - 350g
5) Dagger +15% attack speed - 415g
6) Berserker's Greaves (combine Boots of Speed and Dagger) +25% Attack speed and Enhance movement 2
7) Ruby Crystal +200 hp - 475g
8) Long Sword +10 damage - 415g
9) Phage (combine Ruby Crystal and Long Sword) +250 hp, +18 damage, Passive: 25% chance on hit to reduce move speed of enemy by 40% for 2.5 seconds - 425g
10) Brawler's Gloves +8% Critical Strike - 400g
11) Dagger +15% Attack Speed - 415g
12) Zeal +20% attack speed, +10% Critical Strike, +8% Movement Speed - 375g
13) Trinity Force (combine Zeal, Phage and Sheen) +20 Damage, +30 Ability Power, +25% Attack Speed, +12% Crit Chance, +12% Move Speed, +300 Health, +300 Mana, UNIQUE Passive: 25% chance on hit to slow the target by 50% for 2.5 seconds; on cast, increases your base Attack Damage by 150% for one attack.
After this you have several options - here is a sample of one build I use regularly.
14) BF Sword +50 damage - 1850g
15) Cloak of Agility +18% Critical Strike - 880g
16) Pickaxe +25 damage - 975g
17) Infinity Edge (combine BF Sword, Cloak of Agility, and Pickaxe) +80 Attack Damage +20% Critical Strike UNIQUE Passive: Critical hits now deal 250% damage instead of 200%. - 375g
18) Recurve Bow +40% Attack Speed - 1050g
19) Long Sword +10 damage - 415g
20) Last Whisper (combine Recurve Bow and Long Sword) +20 Attack Damage +40% Attack Speed UNIQUE Passive: Attacks penetrate 40% of the defender's armor - 500g
At this point you have 4 of your 6 slots full, and it is rare to progress past this point in the game. But, if you do, another couple options for you.
21) BF Sword +50 damage - 1850g
22) Long Sword +10 damage - 415g
23) Black Cleaver (combine BF Sword and Long Sword) +75 Attack Damage Passive: Physical attacks reduce your target's Armor by 12 for 5 seconds, (maximum 5 stacks). - 800g
24) BF Sword +50 damage - 1850g
25) Bloodthirster (combines BF Sword) +60 Attack Damage +15% Lifesteal Passive: Gain an additional 1 Physical Damage and 0.25% Lifesteal per kill. Maximum of +40 Damage and 10% Lifesteal. Bonuses are lost upon death. - 1350g
These can be swapped up a bit depending on preference and need in the game, but this is one variation of an attack item build with Corki.
Skill Build:
1) Phosphorus Bomb (1)
2) Valkyrie (1)
3) Phosphorus Bomb (2)
4) Valkyrie (2)
5) Valkyrie (3)
6) Missile Barrage (1)
7) Valkyrie (4)
8) Phosphorus Bomb (3)
9) Valkyrie (5)
10) Phosphorus Bomb (4)
11) Missile Barrage (2)
12) Phosphorus Bomb (5)
13) Gatling Gun (1)
14) Gatling Gun (2)
15) Gatling Gun (3)
16) Missile Barrage (3)
17) Gatling Gun (4)
18) Gatling Gun (5)
Basic Playing Strategy:
I've already outlined some basic principles from the starting items, but here I want to go into more detail with each of the roles you will find yourself in.
Gold Farming/Pushing:
Valkyrie is a farmer's wet dream. By level 3 you can kill all the ranged minions with the DoT and by level 5 you can farm an entire wave of minions. This will also push your minions very quickly in a lane towards the enemy turrets. The best way to use this is starting just behind your melee minions in roughly the center of the melee - when your team's minions and the enemy team's minions engage and start duking it out, you should be able to reach to the ranged minions with your Valkyrie, damaging everything in a straight line and catching most, if not all of the enemy team's minions. Typically you want to wait until the ranged minions have just started attacking to make sure you a) catch all the minions and b) don't take collateral damage from the minions attacking you.
At early levels, you can combine using Valkyrie and Phosphorus Bombs to nuke an entire minion wave. This ensures you get the last hits on all the minions, and will enable you to farm very quickly to get all those juicy items.
Combat/Laning:
Early game:
Use Phosphorus Bombs as your main harass along with your basic attack. If you face melee opponents in your lane, it becomes relatively easy to harass them every time they try to come in and kill a minion. Doing this a few times can put them around half health relatively quickly and give you lane control. If you face ranged heroes, you will be using primarily your Phosphorus Bombs. Try and catch them towards the middle to outer edge of the AoE to minimize chances of retaliation. Once an enemy champion is heavily damaged, you can use Valkyrie to go over the minions, pop a Phosphorus Bomb on the enemy champions and a basic attack or two. If this doesn't kill them, chances are it will force them back to base to heal. The benefit of doing this is your Valkyrie is farming minions at the same time, ringing that sweet sound in your coffers. As for Valkyrie being used as a nuke early game, I find it to be unreliable at best, and dangerous at worst. The air-time delay gives your opponents plenty of time to get out of the way and unload on you if they are at full health. I would maintain Valkyrie be used only when your opponents are in the danger zone early game - and mostly to get you into range for your other nukes, to chase, run away, or preferably farm minions.
Mid game:
I consider mid game to start for Corki when he completes his Sheen, Phage, and Berserker Greaves. If you have been following the early game advice, chances are you have farmed decently well and maybe even gotten a champion kill or two. By now you have hit level 6 and started getting Missile Barrage to accumulate. Something to note - every 4th missile from Missile Barrage is a BIG missile - which means bigger AoE and more damage. If you are fully charged, it isn't a bad idea to 'prep' the 4th missile to be the next on your list for a gank or team fight. By now you can usually spot a hero or two that is either alone, or perhaps below 75% health. That sounds like a great place to start your killing spree.
Initiation:
Generally speaking you want to position yourself so that you can Valkyrie really close to the enemy champion. If they try and run away, you have a really good chance at getting a Phage/Trinity Force slow proc on them. If they try and fight, well they are in for a surprise.
Ability rotation:
First thing you do when you land is drop a Phosphorus Bomb right on top of them. This gives the enemy a 35% miss chance for 4 seconds and prevents them from stealthing if they are able. In my skill build you don't have Gatling Gun yet, but no worries, you have plenty of damage coming. Your Phosphorus Bomb has proc'd your sheen ability, so attack the enemy hero with your basic attack. You have probably done 1/3rd to half of their hp in damage. Now fire a missile from your Missile Barrage. If there are any minions left nearby, (or other champions) this will be a nice chunk of damage to everything in the area. You will auto attack again, probably once - maybe twice, and now your sheen is off cooldown. Another rocket and auto attack will finish off the hero, if they weren't dead already from your initial strike.
Generally speaking, this 'alpha' can easily do 800-1000 damage very quickly, with plenty of sustained damage if needed. If perchance, they manage to survive, you can chase them and save up another Phosphorus Bomb, Valkyrie to pursue, or try and finish them off with a missile at range if you have good aim.
Tip: For Turret Hugging Enemies
If your enemy is hugging their turret for dear life (as well they should be!) - you have a couple options available. If you are feeling pretty beefy on your hp, you can just Valkyrie in and initiate your 'alpha'. But, you will take a lot of turret damage in the process and if they can stun you, you could possibly die giving them a kill and possible bonus gold from your killing streak. What I recommend is circling off to the side in the forest area. Your rockets will go through the trees and the enemy champion will still be in range. Plus if you stand right at the edge of the treeline, you should get vision, if dimly, of where the enemy champion is at, and chances are they won't see it coming.
Late game:
By now, you are probably the carry for your team. Why? Because you can farm entire waves of minions in a matter of seconds, and probably take on enemy heroes 1v2, maybe even 1v3. Your damage output is phenomenal, but there is a catch. You can be a little squishy when focused, and by now you should be seeing most of the fights as either large ganks, or large team fights.
If you get focused:
This is bad - generally your defense is to Valkyrie away... quickly. If they keep chasing you, your hope is that your team will be able to beat on them and take their focus away or kill them, while you can add your missiles at a fairly safe range. If you simply have no hope of getting away clean, try and do as much damage as possible to enable another teammate to get the kill. Pop Phosphorus Bomb, Gatling Gun (make sure you are faced the right way if you do) and spam your missiles.
Ideally, you do not want to be in the center of the battle, where all the stuns, knockbacks, and AoEs are taking place, unless you can solo their team. The best place is right on the outside of the melee combat, where you can do massive amounts of damage to everyone in range. Pop your Gatling Gun and Phosphorus Bomb, and spam your Missile Barrage while attacking the most dangerous champion. Use Valkyrie to chase or flee depending on how the battle is going. Again - it is not recommended to use Valkyrie as a DoT offensively in a team battle. Valkyrie's biggest advantage is its mobility, and it will save you from many deaths, and get you kills where other champions would fail. The exception to this might be if you find the team battle is spreading out with the strong champions chasing the heavily damaged ones. If your teammate is running away and being pursued by an enemy champion, use the same initiation tactic by using Valkyrie to fly over the champion. This accomplishes two things. One, you place a dot and can start your 'alpha'. Two, you block the enemy from pursuing your ally. Trinity Force/Phage will most likely get a proc after a couple hits and prevent them from getting the last hit on your low health friend.
Tip for catching the last hit on a fleeing champion:
In a team battle it isn't uncommon for the champions who get hurt first to run away with scant hp left. One option you could use is Valkyrie to go over the battle and try and get a parting shot off. It may be better to go at an angle where your missiles won't encounter any obstructions, like for instance a minion wave coming to join the fray. Use the surrounding forest areas to get better angles, or at the very least go to the sides of the lane instead of straight down the middle.
Running away:
Forest areas are very handy when running away as you can vault over trees with Valkyrie while most heroes have to path around them. Generally speaking you can probably outrun most heroes by simply using Valkyrie to fly towards the nearest turret. But if you are getting slowed, that might not be enough. Use your Phosphorus Bomb against a physical attacking hero to give yourself a chance for the enemy to miss while you continue to run. The object is to live long enough to use Valkyrie again, or make them dive through a turret to get to you. If they chase into a turret, you might be able to do enough damage with the turret combined to make sure they don't survive, and in some cases you can finish them off first.
This concludes my guide - enjoy playing one of the best champions in League of Legends!
I am not going to get into runes or mastery - to each his own. This guide is a how to guide on itemizing and playing Corki to own in just about every game (for the record I go complete offensive mastery and I have no runes yet to play with).
Starting Summoner Skills:
Teleport
Heal
Starting item build:
Sapphire Crystal - 400g
(optional) Healing Potionx2 -35g each
Reason for starting items:
It is very easy to establish early lane dominance with Corki if you can harass well. Those moves are of course dependent upon your mana pool (243 base). Starting with the Sapphire Crystal gives you 443 mana at level 1.
Phosphorus Bomb - cost 70 mana at level 1 for 80 damage.
243 / 70 = 3 Phosphorus Bombs (240 damage in harassment)
443 / 70 = 6 Phosphorus Bombs (480 damage in harassment)
This does not account for mana regeneration or the mana you gain from leveling.
In short, at level 1 you have enough mana pool to nuke a champion back to the well. By using them often, it is typically enough to force the other champions away from the minions so that you can farm freely and keep the enemy from farming. Also, when you start using Valkyrie, you have enough mana to hit the minion wave, and drop a bomb when you land to either farm the minions quickly or to hit the enemy champion for more harassment.
Item plan:
The idea is to build Sheen as quickly as possible, even before boots. This will soon lead to having a Trinity Force as your first big item. After getting Sheen, I usually go Berserker Greaves for the move speed and attack speed, which works really well for hero ganking, then getting Phage (Ruby Crystal first, then Long Sword), then Zeal (Brawler's Gloves then Dagger), and finally finishing Trinity Force. With these two items you are a major force to be reckoned with early through mid game.
Reasoning for Sheen/Trinity Force first:
Sheen gives you an awesome burst combo early game. Your abilities proc Sheen often, and combining your attack with your spells make for a potent hero killing combination. Trinity Force gives you some really nice abilities for burst and chasing heroes. Yes, you do have Valkyrie, but having a slow makes a big difference between getting the kill quickly or chasing a hero halfway across the map and possibly running into their other teammates. The proc from Sheen gives you a nice burst when you Valkyrie in and start to unload (as I will describe in detail later) and the slow from Phage will make sure they won't be able to get away, with only few exceptions. The overall stats give you everything you could ask for offensively - hp, mana, damage, AP, attack speed, and move speed. After your initial strike, using your rockets in battle will continue to proc sheen for sustained burst.
Item path - in order:
1) Sapphire Crystal +200 mana (start) - 400g
2) Amplifying Tome +20 Ability Power - 435g
3) Sheen (combine Sapphire Crystal and Amplifying Tome) +250 mana and 25 AP - 425g
4) Boots of Speed +1 Enhance Move Speed - 350g
5) Dagger +15% attack speed - 415g
6) Berserker's Greaves (combine Boots of Speed and Dagger) +25% Attack speed and Enhance movement 2
7) Ruby Crystal +200 hp - 475g
8) Long Sword +10 damage - 415g
9) Phage (combine Ruby Crystal and Long Sword) +250 hp, +18 damage, Passive: 25% chance on hit to reduce move speed of enemy by 40% for 2.5 seconds - 425g
10) Brawler's Gloves +8% Critical Strike - 400g
11) Dagger +15% Attack Speed - 415g
12) Zeal +20% attack speed, +10% Critical Strike, +8% Movement Speed - 375g
13) Trinity Force (combine Zeal, Phage and Sheen) +20 Damage, +30 Ability Power, +25% Attack Speed, +12% Crit Chance, +12% Move Speed, +300 Health, +300 Mana, UNIQUE Passive: 25% chance on hit to slow the target by 50% for 2.5 seconds; on cast, increases your base Attack Damage by 150% for one attack.
After this you have several options - here is a sample of one build I use regularly.
14) BF Sword +50 damage - 1850g
15) Cloak of Agility +18% Critical Strike - 880g
16) Pickaxe +25 damage - 975g
17) Infinity Edge (combine BF Sword, Cloak of Agility, and Pickaxe) +80 Attack Damage +20% Critical Strike UNIQUE Passive: Critical hits now deal 250% damage instead of 200%. - 375g
18) Recurve Bow +40% Attack Speed - 1050g
19) Long Sword +10 damage - 415g
20) Last Whisper (combine Recurve Bow and Long Sword) +20 Attack Damage +40% Attack Speed UNIQUE Passive: Attacks penetrate 40% of the defender's armor - 500g
At this point you have 4 of your 6 slots full, and it is rare to progress past this point in the game. But, if you do, another couple options for you.
21) BF Sword +50 damage - 1850g
22) Long Sword +10 damage - 415g
23) Black Cleaver (combine BF Sword and Long Sword) +75 Attack Damage Passive: Physical attacks reduce your target's Armor by 12 for 5 seconds, (maximum 5 stacks). - 800g
24) BF Sword +50 damage - 1850g
25) Bloodthirster (combines BF Sword) +60 Attack Damage +15% Lifesteal Passive: Gain an additional 1 Physical Damage and 0.25% Lifesteal per kill. Maximum of +40 Damage and 10% Lifesteal. Bonuses are lost upon death. - 1350g
These can be swapped up a bit depending on preference and need in the game, but this is one variation of an attack item build with Corki.
Skill Build:
1) Phosphorus Bomb (1)
2) Valkyrie (1)
3) Phosphorus Bomb (2)
4) Valkyrie (2)
5) Valkyrie (3)
6) Missile Barrage (1)
7) Valkyrie (4)
8) Phosphorus Bomb (3)
9) Valkyrie (5)
10) Phosphorus Bomb (4)
11) Missile Barrage (2)
12) Phosphorus Bomb (5)
13) Gatling Gun (1)
14) Gatling Gun (2)
15) Gatling Gun (3)
16) Missile Barrage (3)
17) Gatling Gun (4)
18) Gatling Gun (5)
Basic Playing Strategy:
I've already outlined some basic principles from the starting items, but here I want to go into more detail with each of the roles you will find yourself in.
Gold Farming/Pushing:
Valkyrie is a farmer's wet dream. By level 3 you can kill all the ranged minions with the DoT and by level 5 you can farm an entire wave of minions. This will also push your minions very quickly in a lane towards the enemy turrets. The best way to use this is starting just behind your melee minions in roughly the center of the melee - when your team's minions and the enemy team's minions engage and start duking it out, you should be able to reach to the ranged minions with your Valkyrie, damaging everything in a straight line and catching most, if not all of the enemy team's minions. Typically you want to wait until the ranged minions have just started attacking to make sure you a) catch all the minions and b) don't take collateral damage from the minions attacking you.
At early levels, you can combine using Valkyrie and Phosphorus Bombs to nuke an entire minion wave. This ensures you get the last hits on all the minions, and will enable you to farm very quickly to get all those juicy items.
Combat/Laning:
Early game:
Use Phosphorus Bombs as your main harass along with your basic attack. If you face melee opponents in your lane, it becomes relatively easy to harass them every time they try to come in and kill a minion. Doing this a few times can put them around half health relatively quickly and give you lane control. If you face ranged heroes, you will be using primarily your Phosphorus Bombs. Try and catch them towards the middle to outer edge of the AoE to minimize chances of retaliation. Once an enemy champion is heavily damaged, you can use Valkyrie to go over the minions, pop a Phosphorus Bomb on the enemy champions and a basic attack or two. If this doesn't kill them, chances are it will force them back to base to heal. The benefit of doing this is your Valkyrie is farming minions at the same time, ringing that sweet sound in your coffers. As for Valkyrie being used as a nuke early game, I find it to be unreliable at best, and dangerous at worst. The air-time delay gives your opponents plenty of time to get out of the way and unload on you if they are at full health. I would maintain Valkyrie be used only when your opponents are in the danger zone early game - and mostly to get you into range for your other nukes, to chase, run away, or preferably farm minions.
Mid game:
I consider mid game to start for Corki when he completes his Sheen, Phage, and Berserker Greaves. If you have been following the early game advice, chances are you have farmed decently well and maybe even gotten a champion kill or two. By now you have hit level 6 and started getting Missile Barrage to accumulate. Something to note - every 4th missile from Missile Barrage is a BIG missile - which means bigger AoE and more damage. If you are fully charged, it isn't a bad idea to 'prep' the 4th missile to be the next on your list for a gank or team fight. By now you can usually spot a hero or two that is either alone, or perhaps below 75% health. That sounds like a great place to start your killing spree.
Initiation:
Generally speaking you want to position yourself so that you can Valkyrie really close to the enemy champion. If they try and run away, you have a really good chance at getting a Phage/Trinity Force slow proc on them. If they try and fight, well they are in for a surprise.
Ability rotation:
First thing you do when you land is drop a Phosphorus Bomb right on top of them. This gives the enemy a 35% miss chance for 4 seconds and prevents them from stealthing if they are able. In my skill build you don't have Gatling Gun yet, but no worries, you have plenty of damage coming. Your Phosphorus Bomb has proc'd your sheen ability, so attack the enemy hero with your basic attack. You have probably done 1/3rd to half of their hp in damage. Now fire a missile from your Missile Barrage. If there are any minions left nearby, (or other champions) this will be a nice chunk of damage to everything in the area. You will auto attack again, probably once - maybe twice, and now your sheen is off cooldown. Another rocket and auto attack will finish off the hero, if they weren't dead already from your initial strike.
Generally speaking, this 'alpha' can easily do 800-1000 damage very quickly, with plenty of sustained damage if needed. If perchance, they manage to survive, you can chase them and save up another Phosphorus Bomb, Valkyrie to pursue, or try and finish them off with a missile at range if you have good aim.
Tip: For Turret Hugging Enemies
If your enemy is hugging their turret for dear life (as well they should be!) - you have a couple options available. If you are feeling pretty beefy on your hp, you can just Valkyrie in and initiate your 'alpha'. But, you will take a lot of turret damage in the process and if they can stun you, you could possibly die giving them a kill and possible bonus gold from your killing streak. What I recommend is circling off to the side in the forest area. Your rockets will go through the trees and the enemy champion will still be in range. Plus if you stand right at the edge of the treeline, you should get vision, if dimly, of where the enemy champion is at, and chances are they won't see it coming.
Late game:
By now, you are probably the carry for your team. Why? Because you can farm entire waves of minions in a matter of seconds, and probably take on enemy heroes 1v2, maybe even 1v3. Your damage output is phenomenal, but there is a catch. You can be a little squishy when focused, and by now you should be seeing most of the fights as either large ganks, or large team fights.
If you get focused:
This is bad - generally your defense is to Valkyrie away... quickly. If they keep chasing you, your hope is that your team will be able to beat on them and take their focus away or kill them, while you can add your missiles at a fairly safe range. If you simply have no hope of getting away clean, try and do as much damage as possible to enable another teammate to get the kill. Pop Phosphorus Bomb, Gatling Gun (make sure you are faced the right way if you do) and spam your missiles.
Ideally, you do not want to be in the center of the battle, where all the stuns, knockbacks, and AoEs are taking place, unless you can solo their team. The best place is right on the outside of the melee combat, where you can do massive amounts of damage to everyone in range. Pop your Gatling Gun and Phosphorus Bomb, and spam your Missile Barrage while attacking the most dangerous champion. Use Valkyrie to chase or flee depending on how the battle is going. Again - it is not recommended to use Valkyrie as a DoT offensively in a team battle. Valkyrie's biggest advantage is its mobility, and it will save you from many deaths, and get you kills where other champions would fail. The exception to this might be if you find the team battle is spreading out with the strong champions chasing the heavily damaged ones. If your teammate is running away and being pursued by an enemy champion, use the same initiation tactic by using Valkyrie to fly over the champion. This accomplishes two things. One, you place a dot and can start your 'alpha'. Two, you block the enemy from pursuing your ally. Trinity Force/Phage will most likely get a proc after a couple hits and prevent them from getting the last hit on your low health friend.
Tip for catching the last hit on a fleeing champion:
In a team battle it isn't uncommon for the champions who get hurt first to run away with scant hp left. One option you could use is Valkyrie to go over the battle and try and get a parting shot off. It may be better to go at an angle where your missiles won't encounter any obstructions, like for instance a minion wave coming to join the fray. Use the surrounding forest areas to get better angles, or at the very least go to the sides of the lane instead of straight down the middle.
Running away:
Forest areas are very handy when running away as you can vault over trees with Valkyrie while most heroes have to path around them. Generally speaking you can probably outrun most heroes by simply using Valkyrie to fly towards the nearest turret. But if you are getting slowed, that might not be enough. Use your Phosphorus Bomb against a physical attacking hero to give yourself a chance for the enemy to miss while you continue to run. The object is to live long enough to use Valkyrie again, or make them dive through a turret to get to you. If they chase into a turret, you might be able to do enough damage with the turret combined to make sure they don't survive, and in some cases you can finish them off first.
This concludes my guide - enjoy playing one of the best champions in League of Legends!
