Yasuo vs Malzahar

Hit twice with Steel Tempest (Q), on minions if needed, to charge the whirlwind. Cast it during Sweeping Blade (E): the strike becomes a circle.

Keep moving before taking a trade: Way of the Wanderer (passive) builds your shield while you move, and it triggers on the first hit you take.

Chain Sweeping Blade (E) on different targets to reposition or dodge: each target has its own cooldown, so the spell comes back almost instantly.

Save Wind Wall (W) for a projectile that decides the teamfight, like Jinx's ult, rather than for poke: it blocks for 4 seconds, on a 25 to 17 second cooldown.

Watch for your allies' knock-ups: Last Breath (R) can be cast on any airborne champion, whether the knock-up comes from your whirlwind or Malphite's ult.

Get out of the Call of the Void (Q) zone quickly: its two portals fire after a short delay, and their projectiles silence you.

If you have CC, hit him first with a cheap attack, then wait a moment: Void Shift (passive) still ignores CC right after the first damage.

Stay away from minions hit by Malefic Visions (E): if they die, the visions jump to the nearest enemy, and his Voidlings follow them.

Take your trades before he hits level 6: after that, Nether Grasp (R) can lock you down from range while his team hits you.

When he casts Nether Grasp (R) on an ally, focus him: he channels in place, and any CC interrupts him and frees your ally.