If you want to knock this out quickly, go in to training mode and play as Unlimited Hakumen. Once it begins, press pause and go to the third set of parameters titled "Basic Parameters 2" and set "Counter Hit" to "Force Counter Hit" and "Negative Penalty" to "Always Active". Now, do half circle back + forward + C (
on default controls) and charge the distortion fully. It should do 6,000 damage per slash if you're next to the opponent. Should take less than 5 minutes if done correctly.