Well, the acid caster is technicaly a "the way god intended" old marty wraps spellcaster with added effort and added benefits of actualy involving a god instead of just prepping old MW everywhere. I don't doubt the power. The unique thing that EM brings to Hex is the ability to stone the revenants, so I was thinkning along horse thief lines of "screw the hazard I got IMAWAL", stone litterally everything that moves (well, apart from what I need to level up), kill the other guy first to level up and ding while I'm at it, stone everything and kill stheno.
Which spells out acid caster, except the actual acid caster works better on maps that aren't as cramped as Hex Ruins.
However, I've been rocking goblin sorcerers all over the map, and sorcerers have been really good for me before I unlocked to old bloodmage because their large mana pool allowed me to spam endiswal and IMAWAL while I explore. Old bloodmage totaly obsoleted them, but since he did, PQI's setting me up with them now, and the effortlessly huge mana pool has always been a bit on the powerfull side.
With CB and any spellcasting gear (dragonsoul and especially mage plate) they can pretty much do anythign with mysterea as long as there's not too many magic monsters around. However, I'm not sure it's doable without mystic balance, and I'm also sure it's not doable without WHEYTWUT (to move stuff around). If I stone stuff then there aren't enough bloodpools for plantation, and that might mean fewer plants with clearances - otherwise a string of clearences could certanly take stheno out.
So, in short - a goblin sorcerer with CB and... something, could do it provided he can find wheytwut, and provided Mystic Balance isn't necessary. And EM is only really necessary for IMAWAL, if she wasn't and if I wasn't getting tired of mysterea, it would really be doable with mysterea even if you leave 6ish mosters around for stheno to gobble up and then just unloaded a bunch of weakenings on her...