I pumped my mana up to 40 just because I could. Granted, I didn't have any glyphs left after that, but you know. Could've been higher if I'd prepped JJ together with Mystera, which I actually took.
For the worker minibosses, the magic-immune is easily dealt with using either CYDSTEP or PISORF. IIRC, he doesn't even have first strike, so even GETINDARE is an option. It wasn't at all necessary to bother with, say, Binlor for Stoneskin, for example.
Usually I prefer hybrid brawler sorcerers, but Elves are ok too. Just don't tell Tinker that I said "Elves are ok too", and don't tell Darvin that I passed on JJ.