a good yi is broken

I had 2 games against a yi, the way he 1v5 my team makes me cry, yes I lost. One game I was a 7/0/13 trundle I played the game perfectly from the start, suddenly yi starts to 1v5 our team with ult and youmouss, he dived our carries and 3 shotted them, using his q to avoid cc. Another game that yi did the same but he went hybrid sustain tank, PD,PD,IE,BT,Banshee,Omen. Doesn't matter if we cc him especially in teamfights, he had high sustain and tankiness with banshees and omen. He will did insane damage. Yi if used correctly when fed is broken. The part I QQ and was upset after, I played my role perfectly and had thornmail, 7/0/13. Next game tested yi top, got fed as yi, early cheese, went 31/8/10 had banshees 1v5. This was gold 3 elo.