Ekko vs Lillia

Throw Timewinder (Q) at a champion, then position so the device passes through them again on its way back: it expands into a slowing field, and the return hits again.

Hit with Timewinder (Q) out and back, and weave in the empowered auto from Phase Dive (E): the third hit triggers Z-Drive Resonance (passive), with bonus damage and speed.

Cast Parallel Convergence (W) where the fight will happen, then step into the sphere when it appears: you stun the enemies inside and gain a shield.

Engage, deal your damage, then cast Chronobreak (R): you return to where you were 4 seconds earlier, in stasis, and recover health based on what you lost.

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.