Lillia vs Cho'Gath

Hit with the edge of Blooming Blows (Q), not the center: only the outer edge adds true damage.

Hit enemies with your spells and keep your distance: Blooming Blows (Q) gives you a stack of move speed on each hit, enough to kite and dodge.

Start the fight from range with Swirlseed (E): it damages, slows and reveals, and if it hits nothing, it rolls on to the first enemy or wall.

Before Lilting Lullaby (R), hit as many enemies as you can: Dream-Laden Bough (passive) marks every target of your spells, and only marked ones fall asleep.

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.