There is one more gronn to be slain: Skulloc Soulgrinder.  He keeps himself hidden away, but there is a way to coax him forth.$B$BHe was trained by an ogre warlock known as Vim'gol the Vile, whose grimoire you must retrieve!$B$BVim'gol must be summoned by yourself, and four others, each standing within a different fire ring at his circle.  Find Vim'gol's Circle in the mountains, to the northeast, near the Broken Wilds.$B$BAnd, $N, if you hear Vim'gol talk about growing bigger, get back to the fire rings!