I solo Baal with my sorc. I've got a lvl 88 FO/CL sorc. I'm using a wizard spike and a lidless shield. Enigma armor, arachnid mesh, and shako. I do pretty good. My killing power is not as fast as some but I stay alive pretty well.
I Use pure light sorc with ES maxed and merc with insight great polearm tals mask and Gladiators bane. I die rarely so far . The only monster in worldstone which is light immune is souls and normaly merc takes care of them
(U will never die if ur ES is atleast 90% and ur merc is alive ))