Here's all you need to know:
IF he's Thrust spec, get Croc Tooth dagger and Golden Spear.
If he's Slash spec, get Malice axe and Battler.
If he's Crush spec, good luck I have know idea.
These are the highest damage weapons on the game that I know of. Actually, your dps over time can be the same, but if you're like me and your fights last only a few seconds then you want the most damage upfront quickly, and these weapons are the ones you want.