Kroshius lays in a heap to the northeast, in the Shatter Scar Vale. Take this Fel fire and use it on his remains. The fire should reanimate the fallen infernal. At this point, I fully expect him to kill you and any friends that you may have brought along - and trust me, you will want to bring along some friends. If by some miracle you happen to kill Kroshius, take his infernal core and return it to Niby.
You receive