The vocals as "karthus" question.

So we all know jorn lande did the vocals for pentakill songs, and in this case is referred to as karthus, but my question is, why didnt you guys ask jorn to do the actually voice of in game karthus aswell?

I seeing as you got one of the best hard rock singers to collab on pentakill albums maybe this time youll put him in the game.. maybe?