Hecarim vs Lillia

Cast Devastating Charge (E) far from your target: the longer the run, the farther the knockback and the harder the hit, and Warpath (passive) turns your bonus move speed into AD.

Cast Onslaught of Shadows (R) from range: the fear from the shockwave, at the end of the dash, lasts longer after a long run.

In teamfights, recast Rampage (Q) as soon as it's back: each cast that hits adds a stack, which lowers its cooldown and raises its damage.

Activate Spirit of Dread (W) in the middle of the enemies: you gain armor and magic resist, and heal for part of the damage you and your team deal to them.

Against Blooming Blows (Q), stick to her or back out of range: only the outer edge of the zone adds true damage.

Get out of the center of Watch Out! Eep! (W): the zone deals much more damage there than at the edge.

Dodge her spells, even Swirlseed (E), which rolls to the first enemy: each one marks you for Lilting Lullaby (R), which puts every marked enemy to sleep.

If you have CC, use it on her: with no dash, she relies on the move speed Blooming Blows (Q) gives her for each spell that hits.