That could've been a lot harder. My practice run was a close call by comparison, but I blame that on Frank the Zombie.
Between preps and drops, there were health boosters, Fire Heart, Crystal Ball, Bear Mace, Keg of Mana, Jehora, and Pactmaker. Really good all around. CYDSTEP was welcome, but not needed. LEMMISI dropping really early meant that I could actually use it before sending it off, which is pretty novel.
First of all, I didn't prep any altars because the penalties are too harsh (except for Binlor, but he's a no-show). Pactmaker+JJ makes 2x health boost and 2x mana boost achievable, so I did that. Combine that with Fire Heart and Crystal Ball, and you are ready to start wailing on the bosses. Unfortunately, no PISORF. If you corrode one boss, you should probably fireball the other one, because the one you're actually attacking directly is taking 2x the damage... Unless you are ok with tanking hits from the other boss, too.
For piety, just make sure to spam WEYTWUT for piety except for when you're fireballing within kill range. High-level meat men, goblins, gorgons, and goo blobs leave you with a pretty long space to spam WEYTWUT before you can score a kill.
The secret subdungeon is pretty good, even if it is just conversion fodder.