Lissandra vs Yasuo Mid Matchup

Why Lissandra is favored

Lissandra counters Yasuo because Ring of Frost and Frozen Tomb are non-projectiles that completely bypass Wind Wall, letting her root Yasuo mid-dash or stun him point-and-click to deny his Last Breath.

How to play as Lissandra

Hold Ring of Frost until Yasuo dashes onto you with Sweeping Blade: rooting him mid-dash or after he exhausts his minion dash targets forces him to eat minion aggro and free counter-poke.

If Yasuo fires an unavoidable tornado at close range, immediately cast Ring of Frost or Frozen Tomb on him before it hits: he is locked out of casting Last Breath while rooted or stunned.

Stand outside your own minion wave so Yasuo cannot use your creeps as dash ramps, and recast Glacial Path early if you anticipate him placing Wind Wall across the claw's path.

Ring of Frost is an instant point-blank area root, not a projectile, so Yasuo's Wind Wall cannot block it when he dashes into melee range with Sweeping Blade.

Frozen Tomb applies a point-and-click stun that ignores Wind Wall, and Yasuo cannot activate Last Breath while snared or stunned even if his whirlwind lands.

How to play as Yasuo

Track Lissandra's claw and throw Wind Wall directly in its trajectory to destroy the projectile before she can reactivate Glacial Path to escape.

Bait out Ring of Frost before committing your tornado: getting rooted in melee range right as your whirlwind lands completely denies you from activating Last Breath.

Glacial Path travels as a projectile claw, so Yasuo's Wind Wall intercepts and destroys the missile upon contact.

Sources

These notes come from r/LissandraMains, checked against the champions' abilities.