Sett vs Cho'Gath

Start your trades with Knuckle Down (Q): you rush toward your target, and your next two autos deal bonus damage based on their max health.

Cast Haymaker (W) right after taking damage: the stored Grit gives you a shield and extra damage, dealt as true damage in the center of the punch.

Don't back too early at low health: Pit Grit (passive) increases your health regen based on your missing health.

Stand between two enemies before Facebreaker (E): grabbed from both sides, they're stunned, otherwise only slowed.

Grab their tank with The Show Stopper (R) and slam them onto their carries: the damage around the impact depends on the bonus health of the target you grab.

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.