I've come up with a side quest world after Khrysalis. I've heard there's a world called Darkmoor, but I have no clue what the world contains. I'm just using it's name because it sounds appropriate.
Story: Before being defeated, Morganthe corrupted your shadow magic. It should've driven you beyond the breaking point. Making you insane like so many others, but instead a shadow version of yourself breaks off and it is happening to all the wizards who have learned the way of the shadow. All the shadow duplicates run amok in Darkmoor At the end you must solo your duplicate. It's statistics are identical to yours, however it has many shadow spells and tricks up it's sleeve. Like the ability to split itself into 4. It'd be alike the Loremaster and you can learn different shadow spells from it.