fb7d1f71__Walkthrough_by_metzomagic_com__Why_and_How
[Who] Kraka-Tur [Where] The Void [Why and How] 
If you have found and read his journal in the Lair of Bellerogrim, Kraka-Tur will join you, but he's pretty much crap in a fight.
Arcanum Walkthrough - Just One of Many Reviews on this Website Walkthrough by metzomagic.com
Why and How