Irelia vs Yasuo

Mark your targets with Flawless Duet (E) or Vanguard's Edge (R) before Bladesurge (Q): if the target is Unsteady or dies to it, its cooldown resets.

Before a trade, hit minions with Bladesurge (Q) to stack Ionian Fervor (passive): each stack gives attack speed, and at max stacks your autos hit harder.

Place the two blades of Flawless Duet (E) on either side of your target: only enemies caught between them are stunned.

Use Defiant Dance (W) to absorb a burst: you take less damage while charging, and the longer you hold it, the harder the release hits.

Hit him with a cheap attack to trigger the Way of the Wanderer (passive) shield, then start the real trade: otherwise, it absorbs your best damage.

If you have projectiles, save them for after Wind Wall (W): it blocks them all for 4 seconds, on a 25 to 17 second cooldown. Other spells go through it.

Don't stand right behind your minions: each one gives him a target for Sweeping Blade (E), and he gets closer to you with every dash.

Get out of the line of his whirlwind, the third Steel Tempest (Q): without a knock-up, he can't cast Last Breath (R).

Judge his threat by his crit items more than his level: Way of the Wanderer (passive) raises his critical strike chance, so each crit item does more for him.