Yasuo vs Xerath

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.

Keep minions between you and Xerath: Shocking Orb (E) stuns the first enemy hit, for longer the farther it has traveled.

Don't stand still, and change direction often: Arcanopulse (Q) hits a target moving forward or backward in a straight line much more easily.

If you can engage, go in while he charges Arcanopulse (Q): he slows down by up to 50%, and he has no dash to escape.

If you have CC and can reach him during Rite of the Arcane (R), use it: he channels the ult, and interrupting it stops his shots.