I'd put my money on Arbiter, honestly. God that's a boring weapon. Besides Trinity Smash and Drop/Tremor, the thing is useless and Drop JCs are STILL broken in the PC release. At least when you JC a Showdown, it deals damage and gains style.
Both are pretty awful though. I mean seriously only six and seven moves respectively? That's half of nearly every other one of Dante's weapon in the DMC series.