Disgaea 2: Cursed Memories

The weapon 100 Fists is rather high rank (so high-level specialists), can be purchased, and always has an Armsmaster on it (level 42 unsubdued, in it's case)

100Fists,
CoO5 has TONS.
Or you can also buy from store.

imo, 1900 is too much, 300~ is more than enough.

Stealing the 100 Fists in Cavern of Ordeals 5 Requires that you at least are able to finish the map, and be able to steal them all. If you can pull that off, that's the fastest way to at least gather the items with Armsmasters on them.

The fastest way to gather them off the gloves, Use a high level mage (For the range) And a few heavy knights (Throw distance. If you gathered with the above method, then you should have plenty heavy knights)

Get yourself a Mothman, and stick anything that gives him movement speed. (Accelerators, Angel sandals, etc.) And use the mage to clear the exit gate, And just run your mothman there. If you use a weight on the mothman, then take it off, you will have an additional +1 Movement.

Just do this on all your 100 Fists, and you should get the 1900 pretty quickly.

As for Atashii, 1900 is GREAT. I would much rather spend an hour getting to 255 mastery instead of days, with any given character.

Just buy... 20 100 fist, you will have... 84 armsmasters each... really quickly. see ya.