Is Garrosh possessed, or just insane?

[Porimlys]

Neither, he's just kind of a dick.

[zito]

to be honest he probably won't die. Some sha corruption will come out of him when we fight him and get him to X% health and we kill that.

Then he goes back to being warcheif and jaina blows up the world.

[Florena]

He's corrupted by his own pride, power, and drive to live up to his father's legacy. But not corrupted by demons or sha etc.

[Feral Camel]

I would not call him insane.
Can't he just be a jerk?

[DEWstar]

Garrosh is just his daddy 2.0. He seeks out demon empowerment then at the very end will do exactly what his dad did, sacrificing himself taking out a big baddy. Cut to memorial scene of Thrall and his boo being sad, they then name their kid Garrosh. BoOooomm!