An Idea for Yasuo ?

Passive: Way of the Wanderer

RESOLVE: Yasuo generates 1% of his maximum Flow for every 70 / 60 / 50 units he travels by any means, requiring a total of 7000 / 6000 / 5000 units traveled to obtain maximum Flow. At maximum Flow, the next instance of champion or monster damage against Yasuo consumes all of his Flow and shields him for 50 - 475 (based on level) damage for up to 1 second.

INTENT: Yasuo's critical strike chance is doubled, but his critical strikes deal 90% damage, reduced to 75% damage on Steel Tempest.

MOMENTUM: As Yasuo wears down his opponents, it becomes easier to fink weaknesses in their defenses. Yasuo gains bonus critical strike chance based on his opponent's missing health, maxing at +20% (+10% per rank in Last Breath) when his opponent falls to 50% health or less. Yasuo's critical strikes deal 80% bonus damage instead of the normal 100%.

Q: Steel Tempest RANGE: 475(Strike) / 900(Tornado) / 375(Spin) COOLDOWN: 4

PASSIVE: Increase Yasuo's Critical Strike Damage by 10/20/35/50/70%

ACTIVE: Yasuo thrusts his sword forward, dealing physical damage to all enemies in a line. Steel Tempest can critically strike and will apply on-hit effects to the first enemy hit.

Hitting an enemy grants Gathering Storm for 8 seconds. At 2 stacks, Yasuo's next Steel Tempest is empowered and will consume all stacks.

EMPOWERED: Steel Tempest unleashes a whirlwind that travels an extended distance, dealing the same damage and knocking airborne all enemies hit.

PHYSICAL DAMAGE: 10 / 20 / 40 / 70 / 110 (+ 110% AD)

Yasuo can cast Steel Tempest during Sweeping Blade to change the area of effect to a circle around him, which does not benefit from Empowered's extended range. The cooldown and cast time of Steel Tempest is reduced by 「 1% for every 1.6725% bonus attack speed 」, down to a maximum 66% reduction.

W: Wind Wall RANGE: 400 COOLDOWN: 30 / 27 / 24 / 21 / 18 WALL WIDTH: 400 at all ranks

ACTIVE: Yasuo creates a gust of wind that travels forward to form a wall in front of him. The wall slowly drifts forward 50 units over 3.75 seconds, blocking all enemy projectiles with the exception of turret attacks.

Wall now forms directly in front of Yasuo rather than inside of him

E: Sweeping Blade RANGE: 475 STATIC COOLDOWN: .3 seconds at all ranks ON-TARGET COOLDOWN: 12 / 11 / 10 / 9 / 8

ACTIVE: Yasuo dashes a fixed distance in the direction of the target enemy, dealing magic damage and marking them briefly. The speed of the dash scales with Yasuo's bonus movement speed. Yasuo cannot use Sweeping Blade on a marked enemy.

Each cast increases the next dash's base damage by 25% for 5 seconds, up to 50% bonus damage.

MAGIC DAMAGE: 50 / 60 / 70 / 80 / 90 (+ 30% bonus AD) (+ 70% AP)

LAST BREATH: RANGE: 1200 COOLDOWN: 80 / 55 / 30

ACTIVE: Yasuo blinks to the nearest visible airborne enemy champion to the cursor, instantly generating maximum Flow. Upon arriving, he suspends all nearby airborne enemies for 1 second and deals them physical damage.

For the next 15 seconds, Yasuo's critical strikes ignores 50% of his targets' bonus armor. Casting Last Breath clears all stacks of Gathering Storm.

For the next 10 seconds, Yasuo's Sweeping Blade mark has a MASSIVELY reduced cooldown against targets affected by his last breath (1 second).

I'd write more about the specific thoughts, but TLDR I wanted to push him to more late game power and less early game. Hope to get some discussion going in the comments :)