How to obtain
Talk to the Umbra NPC and complete the first quest. After completing the first quest, go back to Umbra, and talk to him again, you'll receive the second and final quest, which is defeating him.
The Quest (Part 1)
The quest contains:
Kill 50 thugs
Obtain 30,000 Ucoins
The Quest (Part 2)
Defeat the Umbra Boss
On killing the boss you might get one of the two items, Ancient Sword (For Yasuo) and Azakana Mask (For Yone).
After getting an item, you need to talk to the Umbra NPC who will give you the spec accordingly to your item. (If you have the mask, you get Yone. If you have the sword, you get Yasuo.)
This is the same as Yone
Moveset
M1/LMB The User executes 3 swift slashes. This does 45 damage in total and has a 5 second cooldown.
Q The User jabs their swords at the opponent's chest. This does 15 damage and has a 3 second cooldown.
R+Q/Q+Q/R+R The User lashes out a whirlwind knocking everything in its path aside. This move is only usable if you have hit your Q and R moves on an opponent. This does 30 damage and has a 3 second cooldown.
E Being one with the wind, the User graciously dashes through the opponent, slashing them in the process. This does 20 damage and has no cooldown.
R The User executes a 360-degree wind-bound slash. If you hit this, your Steel Tempest (Q move) will be activated by pressing E or Q again.
T The User swiftly executes multiple consecutive slashes. This does 45 damage and has a 15 second cooldown.
Y The User creates a solid wall of wind that stops any projectiles that come through. This is used purely for defense and does no damage. The cooldown is 20 seconds.
F This move acts like a beatdown (things that are used by the various specs in this game). Dashing at the speed of wind while leaving windy white afterimages. If this connects, it will launch into several consecutive slashes that deal extreme damage. This also bypasses block. This does 200 damage and has a cooldown of 90 seconds.
V The User grabs the opponent and by the neck and jabs them in the chest. The quote can be different, below are the quotes:
"Honor is in the heart, not the name."
"It's just death. Nothing serious."
"I alone decide my fate."
"I'll give you the easy way out."
"Kill me? You can try."
This does 40 damage and has a cooldown of 10 seconds.