So, in Oblivion, if you try to do the Sanguine quest after you befriend Mazoga, the guards go berserk and kill her. I figured out a simple workaround is just to have her follow, then tell her to wait way outside the city, come back, finish the Sanguine quest, and go fetch her. I didn’t see this solution posted anywhere, so I thought I’d share in case anyone else ever runs into this problem.