Abyssal Drain: 120 potency in an AoE.

Overpower: 130 potency in a cone.

Both are GCDs, DRK has slight advantage on GCD speed, but lacks the bonus potency.

Quietus: 210 potency

Steel Cyclone: 200 but restores health akin to Abyssal.
You did not add Darkside or the typical lack of Storms Eye to these numbers. Dark Knight clearly leads outside of Inner Release.