A One Handed Lightening Storm for Crowd Control, a Ice Blast that fills entire corridors and slows enemies down to a crawl and a Dual Cast Fire Blast spell that does 112 points of Fire Damage a second.
Also Summon Dragon Priest and Spectral Dragon.
The Dragon Priest summon is quite powerful, but I'd advise against using it if you do not like ash piles. Whenever he dies or "expires," he leaves inaccessible ash piles on top of the ones leftover from resurrected corpses.
False God! This is the end... the final turn of your Wheel!