Seriously how in the shit is Stannis dead?

Let's recap: Oberyn was a god. Not a single bad thing happened to him. He owned everything and everybody. He was the hero to heroes. His death was sudden.

Stannis lost continually. Parts of his army left, then left more the next ep and more the next ep. They just can't stop ditching the Stanny. He kills his daughter. Everybody fucking hates him. Melisandre abandons him. Ramsay charges and he succumbs to defeat before it even happens. The cherry is that just as Brienne sentences him to death, he accepts it.

I'm sorry but this character is NEVER dead in Game of Thrones. If D&D's collective fifty iq meant to kill him they would have turned him into a prime Mike Tyson first.