Senna vs Soraka

Attack the souls held by the Mist whenever you can: each soul freed with Absolution (passive) increases your AD, attack range and crit chance.

Fire Piercing Darkness (Q) through an ally or an enemy to hit both: the beam heals your allies, and damages and slows enemies in the line.

Cast Last Embrace (W) on a target that's already slowed or immobilized: after a short delay, they and nearby enemies are rooted.

Cast Curse of the Black Mist (E) to engage or escape with your team: allies who enter it are camouflaged, then fast and unselectable.

Cast Dawning Shadow (R) to save an ally across the map: the beam has unlimited range and shields allies.

Dodge Starcall (Q): if it hits a champion, Soraka heals and speeds up, and can pass that heal on to an ally.

Get out of Equinox (E) fast: you're silenced inside, and rooted if you're still there when the zone disappears.

If you can reach her, focus Soraka rather than the ally she heals: she has no dash, and each Astral Infusion (W) costs her health.

Finish your targets in a single burst: Wish (R) heals them wherever they are, and more below 40% health.