Where is Grunax!? I need some lvls. in the Dojo, but I don't know how to find out about what happened to this guy. Is he in the Boogre Prison? I found his son (I think it was his son) who is the guy trying to kill Erathsmador, but I killed him for his bow... (I know I should not be evil, but I wanted that bow!). Anyone know how I complete the quest to find out what happened to him?

You need to fully explore the Boogres Caves.
You'll find out what happened to Grunaxe in there and complete your quest.

Wyv