Corki is a fun AD/Hybrid Carry. He can do massive amounts of damage with basic attacks or with his abilities. He can escape or catch up easily and can take that last bit of health away without ignite with his Missile Barrage. He does damage over time with his Gatling Gun and enemies don't often realize it's killing them so quickly until they have very low health, next chapter will go over all of his abilities.

Phosphorus Bomb reveals a small area and damages enemies, also, any enemies hit will be revealed for a short duration.
Valkyrie is a good escape mechanism while it can do damage or be used to catch up, the long cooldown is bad though, so use it with caution, not too freely.
Gatling Gun is Corki's damage output pre-6. I recommend max it first with early BF Sword because it will do major amounts of damage per second without the enemy realizing until it's too late.
Missile Barrage is Corki's ult. It is a good harass, minions farmer, or killer. It is his main ability being able to use it ever 1.2 seconds, unless out of missiles, then it is about 14 seconds until usable.

Pros
-Good harass
-Good damage
-Escape mechanism
-kills rather quickly
-Can get WAY out of hand
with enough kills

Cons
-Long Cooldown on his escape
-Doesn't do much until 6
-Squishy and easy to kill early
-Easy shutting down pre-B.F. Sword