Soul Driver + SE = BROKEN WHEE!

Pierce is the 3rd highest behind Fury and Torpedo, iirc, maybe 4th depending on elemental advantage for mages.

Pure damage-wise Pierce is BY FAR the most powerful attack in the game on mobs of 6, outdamaging even Fury by ~15%, but there's a ton of overkill at the back of the mob. It still outdamages Fury on 5 mobs although at that point it can come down to equips, and at 4 mobs it falls to between Fury/Cannon power (although at 4 mobs all of the above get outdamaged by 3-4 mobbing skills like Crusher/Brandish/Boomerang Step).

Mage mob attacks are pretty weak; they need elemental bonus to do roughly the damage of most warrior mob attacks.