Viktor vs Ezreal

Poke with Hextech Ray (E), fired in the direction you choose: it hits every enemy in its line, and its upgrade adds an aftershock in its wake.

After Siphon Power (Q), land an auto within 4 seconds: it deals bonus magic damage, and the spell's shield covers you during the trade.

Place Gravity Field (W) in your target's path, then fire Hextech Ray (E): the field slows them, and if they stay in it for 1.25 seconds, they're stunned.

Glorious Evolution (passive) upgrades a spell every 100 Hex Fragments: Hextech Ray (E) to poke and clear, Siphon Power (Q) to survive, Gravity Field (W) to slow.

Place Arcane Storm (R) on grouped enemies: it follows the champions it just damaged on its own, and you can recast it to move it.

Stay behind your minions: Mystic Shot (Q) hits the first enemy, and each time it hits you, all his cooldowns go down.

Go all-in when he has used Arcane Shift (E) to move forward: it's his only escape, on a 26 to 14 second cooldown.

Look for head-on teamfights, behind your frontline: Mystic Shot (Q) stops on the first enemy hit, and Essence Flux (W) on the first champion.

At low health, beware of Trueshot Barrage (R) even far from him: the shot crosses the whole map and hits every unit in its line.