Ezreal vs Locke

Land Mystic Shot (Q) as often as you can: each hit lowers all your cooldowns and adds a Rising Spell Force (passive) stack.

Detonate Essence Flux (W) with a spell rather than an auto: the orb deals its damage either way, but a spell refunds its mana cost plus a bonus.

Save Arcane Shift (E) to escape unless the kill is certain: it's your only way to reposition, on a 26 to 14 second cooldown.

Cast Trueshot Barrage (R) across the map to finish a fleeing target: it hits everything in its line, but deals less to minions and non-epic monsters.

Back instead of staying in lane at low health: Silver Stake (passive) adds damage to his autos that grows with your missing health.

Trade after Ashen Pursuit (E): it's his only instant movement, and its 10-second cooldown only resets if he gets a takedown.

During Soul Ignition (W), only hit him if you can kill him: at the end, he heals back part of the last damage taken, yours included.

Marked by Purgatory (R), stay above its threshold: if you have a heal or a shield, use it, because he seals marked enemies who drop below it.

If the Purgatory (R) artifact lands, hold the area where it fell: by picking it up, Locke raises his execute threshold for each sealed champion, for the rest of the game.