Kha'Zix vs Warwick

Jump on an isolated target with Leap (E), then Taste Their Fear (Q): with no ally nearby, Unseen Threat (passive) marks them and the spell hits much harder.

In teamfights, cast Void Assault (R) to vanish and reposition: the invisibility triggers Unseen Threat (passive), and your next auto damages and slows.

Detonate Void Spike (W) close to you in the jungle or in teamfights: you heal if you're inside the explosion area.

Pick your evolutions to fit the game: evolved Leap (E) resets on each takedown, evolved Taste Their Fear (Q) gains range and a lower cooldown on isolated targets.

Keep your health above 50%: below that, Blood Hunt (W) gives him speed toward you and attack speed, three times more below 25%.

When he drops below 50% health, finish him fast, with CC if you have any: Eternal Hunger (passive) then heals him with each auto, three times more below 25%.

If you have a dash, don't count on it to escape his held bite: Jaws of the Beast (Q) makes him follow all your movement, then leap behind you.

In teamfights, stay behind your tankiest allies: Infinite Duress (R) suppresses the first champion hit, and its range grows with his move speed.

If you have Grievous Wounds, apply it to him: his autos heal him at low health, and Infinite Duress (R) heals him for all the damage it deals.