I ended up dying with this on floor 13, it was a good run and my weapon ended up dealing 264 damage per hit. it was an ethereal staff, wich replaced itself with an ethereal blade upon use. The ethereal blade would also create an ethereal staff when destroyed. This caused the negative effects of the bombstone and hourglass to be ignored, giving me a 800 percent multiplier whith barely any drawbacks.
I love this game to death.