Locke vs Cho'Gath

Cast Ritual Nails (Q) before Ashen Pursuit (E): your hits consume the nails stuck in the target, and each extra nail adds damage.

Finish off wounded targets with autos: Silver Stake (passive) adds magic damage that grows with their missing health.

Activate Soul Ignition (W) at the start of a trade: it costs you health, but at the end, you heal back part of the last damage taken, plus more based on your missing health.

Save Ashen Pursuit (E) for a sure kill or to escape a gank: it's your only instant movement, it has a 10-second cooldown, and only a takedown resets it.

Save Purgatory (R) to finish: it seals marked enemies below a health threshold, and when you pick up the artifact, each sealed champion raises that threshold for good.

Keep moving against him: Rupture (Q) strikes an area on the ground, and an enemy standing still takes a knock-up, damage and a slow.

Punish him when he goes for last hits: Carnivore (passive) restores health and mana for each unit he kills, and he lasts a long time in lane if you let him farm.

If you have range, keep your distance: his kit has no dash, only the slows from Rupture (Q) and Vorpal Spikes (E).

Don't stay in melee range at low health when Feast (R) is up: its true damage ignores your resistances, even if you're a tank.