Theres a bug where master yi kills himself with his on hit effects, heres it all explained!
Also i'm by no means just tryin to whore views, so heres the facts if you just prefer reading them. Bloodrazor doesn't really do much to him, but coupled with rageblade every 2 hits when hes at full stacks hurts him, to the point where he kills himself (Proof of thats in the video) Frozen mallet slows YOU, because when you're chasing someone, it's always best to be slowed as well. Wits end steals YOUR MR so it kinda blows until this bug is fixed. Phantom Dancer makes YOU do 12% less damage to the last person attacked so it really flubbernucks you with the whole dueling thing yi's known for. As funny as it would be, thornmail doesn't actually increase the damage you do to yourself. This bug will be patched in the next patch! Hope this helped inform someone, Have a great day!