"As a child, Yasuo often believed what the others in his village said of him: on the best days, his very existence was an error in judgement; on the worst, he was a mistake that could never be undone."
Like just to begin with, you made the circle jerk of hatred for him cannon. Like you should feel fucking ashamed to actually do that to a character. As a writer I feel embarrassed for you.
Instead of a skilled swordsman who was a once in a generation master of the wind sword, you made him a child and a total loser at that. You killed off the "last master" of the wind technique because yeah it makes sense that a master dies so easily. You skipped around his story and gave him nothing in terms of good lore or any interest in terms of expanding his lore. Whoever did this writing needs to seriously never write again. I'm so totally disappointed in you.