Tryndamere Ult

There's nothing more fun then going against Tryndamere. You demolish him in lane,got a good build going and ready for another stomp. But what's this? He hit 6? Shouldn't be a problem,he wouldn't be able to do anything under CC right? Wrong. Why can Tryndamere ult under hard CC exactly. I understand that he's useless under hard CC,which is what suppose to happen. He shouldn't be able to save himself from making a stupid move like that,only to be CC'd,almost killed,ults then kills the rest of your team. This may sound like just your regular bronze complaining about champion balance.but there is nothing more toxic and demoralizing then seeing a Tryn pop his ult and spinning away after all your hard work to kill him. Plz Rito