I'm by no means a high level player, but this is my first time reaching the Magma Core boss a second time (so floor 18). Shield has 1 haste and I had 73 max health. Doing ~800 damage per turn (shield spirit means that drops a bit tho ofc). 54 block on turn one and ofc haste means that's only going up. More than my max health's worth of healing per turn.
I didn't do much RNG manip with the saves and re-opening chests and shops and such; this is mostly just what it gave me. I actually had another queen cleaver, rage on one cleaver, and another health boost (and some things I have now but got earlier) but some save errors meant I lost ~20 minutes of really lucky progress (was probably 8-10 saves, both auto and manual, that it set me back).
The way the cleavers loop and reactivate each other is fun to watch (well. until it gets tedious waiting to be able to end your turn LOL).Anyway I love this game!