I mean I've gotten through it with Fighter, Berserker, Warlord, Rogue, and Wizard. I'm at 7/10 badges, missing Faithless, Purist, and Feeling Parched. But I seem absolutely unable to do anything new on it. Mostly attempts fall into three categories;
1) I do not get ENDISWAL and I get to a point where every revealed monster will either kill me, or killing it will corner me with Rex.
2) I do get ENDISWAL, but then the monsters are laid out in such a way that I can't get to the ones 1-2 levels above me without using up a lot of resources on removing walls while letting hp regen go to waste. I end up without enough resources to get rid of two bosses. Rex almost always demands all my mana potions, so if Bleaty or Goo shows up, I am pretty much boned.
3) I get ENDISWAL, but then accidentally trip over Rex before he reveals himself, getting me cornered and smooshed even quicker.
PISORF/Bear Mace help to some extents on some tries, but on others, the mace causes more problems than it solves because it's knocking enemies into fog at low levels where that little bit of regen hurts me more than helps me since I'm going after higher level targets. I've tried Monk, Assassin, Vampire, Gorgon, Half-Dragon...
I mean old Rex was a terrible joke but I sort of find myself missing him or someone more like him. I feel like he got a tad overbuffed but no one else ever seems to complain about him so I must just be terrible around him.