Self damage

I was playing in a custom game with my favorite troll build. I call it On Hit Yi. I built a , , , , , (Not in this order) I went to fight baron to see if I could kill it I had 2.5 attack speed without ult. I died. Looked at death recap. Wuju style did 597 true damage to yi. 256 damage was Looked at debuff bar was procked on me, lowered my mage resist by 25, and red buff also burned me. The reason I made this is because this is because I'm wondering should this be happening?