Grim(oire) Business

This quest has you retrieve Vim'gol's Vile Grimoire and return it to Mog'dorg the Wizened.

Objectives
You must retrieve Vim'gol's Vile Grimoire. Deliver it to Mog'dorg the Wizened atop the tower at the Circle of Blood in the Blade's Edge Mountains.

Description
There is one more gronn to be slain: Skulloc Soulgrinder. He keeps himself hidden away, but there is a way to coax him forth.

He was trained by an ogre warlock known as Vim'gol the Vile, whose grimoire you must retrieve!

Vim'gol must be summoned by standing within a fire ring at his circle. Find Vim'gol's Circle in the mountains, to the northeast, near the Broken Wilds.

And, , if you hear Vim'gol talk about growing bigger, get back to the fire rings!

Reward
You will receive on completion, or  at level 70.

Progress
Have you summoned forth Vim'gol the Vile and taken the grimoire from his dead clutches?

Completion
I hesitate to even touch such a tainted thing of evil. Yet read it we must if we are to glean what knowledge it contains and bring forth Skulloc from his hiding place.