I just finished Stealer of Souls today (solo, on Casual) and got my Dragontouched Docent. Sor'jek gave me a Sovereign Rune (apparently not guaranteed on Casual, but it was useless for me so I broke it down), and I'd like to know what I should be aiming for. I'm a Wizard 15/Rogue 2 (aiming for the usual 18/2), Evocation/Conjuration Archmage, mainly solo with a hireling. I'm thinking the Tempest ought to be Exceptional Int, but I'm not sure about the Eldritch and Sovereign.
I'll need to get another Sovereign - which is more economical out of Stealer on Casual with non-guaranteed Sovereign (if no Sovereign, do you get a Tempest or just nothing?) and running Prey repeatedly to combine Tempests?