Mel vs Ahri

Stay back and poke with Radiant Volley (Q): its projectiles explode in an area up to 950 range, and each hit applies Overwhelm.

Land an auto after each spell: Searing Brilliance (passive) adds three projectiles to it per spell cast, and enough Overwhelm executes the target.

Save Rebuttal (W) for a dangerous projectile: the barrier sends it back to its caster, and you gain a shield and move speed.

Hit your target head-on with Solar Snare (E): only the core of the orb roots, the aura around it just slows and damages.

Cast Golden Eclipse (R) to finish from range: it hits every enemy marked by Overwhelm, wherever they are, harder with each stack.

Keep minions between you and her: Charm (E) stops on the first enemy hit, and without it her burst lands far less often.

If you can only dodge one pass of Orb of Deception (Q), dodge the return: it deals true damage, which your resistances don't reduce.

Play hard once she has used the dashes of Spirit Rush (R): she has nothing left to escape with, and its cooldown is 140 to 100 seconds.

When she roams, avoid walking through the jungle alone: Charm (E) then Spirit Rush (R) let her catch an isolated target by surprise.