Mel vs Miss Fortune

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.

Don't stay behind a low-health minion: if Double Up (Q) kills it, the bounce that hits you always crits.

Hit her regularly, even with a small hit: Strut (W) only grants her passive move speed after a few seconds without taking damage.

If you can engage, get on top of her: Miss Fortune has no dash or leap, only the speed from Strut (W).

If you have CC, save it for Bullet Time (R): she channels in place, and interrupting her cancels the remaining waves.