I've tried finding a Yang claw combination that will bug the absorb, but none of them work. Best damage I can deal to her is via Cecil's Silver sword for 200-300. The other sisters are much easier to kill, but if it's a delicate matter of damaging the other sisters enough to finish them in 4 turns, it's really hard to tell. Takes hours of trial and error and damage logging to figure out their max HP.
Just add 15000HP to the default HP that have (I'm too lazy to come up with creative numbers... adding fixed numbers make it easier to recall some changes).
I've likely missed plenty of drops in the Tower itself. The enemies I have killed haven't dropped anything, and there's several I can't kill at all (Icebeasts, Epeegirls).
Not a lot of the drops are new (the best drops are from the Marion and Puppet), and there's quite a bit of drop reuse. Some of the monsters ultimately do require a bit more thought into killing.
One question I'd have is, does Displ change speed back to 16?
No, it does not. Black Hole was originally the intended spell to increase difficulty (resetting speed and Wall/Reflect removal), but that didn't work out. However, Dispel used in a different instance (other than removing Wall/Reflect) intentionally to exploit a particular behavior and as a unintended but the nice result made Sandy a pure White magic user.