Tank DPS Ranking prediction.

[BlueThunder]

DRK have two direct damage buffing skills: Darkside. It's a 15% increase to all damage, but drains MP slowly while active. We also have Dark Arts, which significantly increases the potency of some skills, but it costs a lot of MP to use, so you have to combine it with either Blood Price (tanking with Grit) or Blood Weapon (no Grit). Though speaking of Blood Weapon, that does increase attack speed.

A competent DRK can keep Darkside up at all times, so we constantly get a 15% damage bonus.

Yeah, Blood Weapon increases your attack speed by more than it seems. But it just makes you drain your TP like crazy.