Responses

* yuuki not you kill GOD DAMN WE AUTO CORRECT

Yuuki did try telling him several times early on, Tat-chan blew him off every time. Never mind Yuuki knowing he was hated from the moment he left to go get help. He figured he deserved to finish destroying his leg as punishment, far as I can tell, if that's what obeying Tat-chan required. More than anything, he wanted to be needed by Tat-chan.
Well I would be angry too If I was tat chan, it's not his fault he didn't know anything you kill shouldve told him in the first place