FYI: your biggest mistake in that run was not taking the LEMMISI. Shadow Heart gives +1 mana regen PER TILE - it doubles your mana regen. So even with Mystic Balance you'd easily be turning a big profit with each cast underground, and have some extra tiles on the surface as well.
Fortunately, that build is so strong, that you didn't have many problems anyway. Of course, the real challenge comes in rainbowing the dungeons. It's definitely possible to do... but easy? Definitely not.
You'll be happy to know that you're probably going to steamroll the new dungeon with that exact same build. I wouldn't be surprised if you got it first try.