21 FA and brandish.

It would make more sense to skip slash blast instead of power strike. 30def is also completely useless at higher levels. I maxed FA since I think a 3.04% increase in damage is better than an microscopic increase in def that becomes useless after level 30.

In the long run that makes sense but losing SB would cost you more money than gaining IB, because you would be way slower from 20-45 or so, when Soul Blade catches up to SB's dps on max-size mobs.