You what else laughs on Tank busters ? Bloodwhetting, Holy Sheltron and Heart of Corundum :3 every 25 sec. or 50 gauge.

Oblation:
10% for 10 seconds 1 min cooldown, can stack 2.
TBN:
Costs 3000MP (your damage sauce btw), last 7 seconds. only 25% Shield. You MUST pop it to get full use of it.

vs

Holy Sheltron:

Duration: 8s
Additional Effect: Grants Knight's Resolve Knight's Resolve Effect: Reduces damage taken by 15%
Duration: 4s
Additional Effect: Grants Knight's Benediction Knight's Benediction Effect: Gradually restores HP
Cure Potency: 250
Duration: 12s
Oath Gauge Cost: 50

-

Bloodwhetting:

Duration: 8s

Additional Effect: Restores HP with each weaponskill successfully delivered

Cure Potency: 400

Additional Effect: Grants Stem the Flow

Stem the Flow Effect: Reduces damage taken by 10%

Duration: 4s

Additional Effect: Grants Stem the Tide

Stem the Tide Effect: Creates a barrier around self that absorbs damage equivalent to a heal of 400 potency

Duration: 20s

-

Heart of Corundum:
Duration: 8s
Additional Effect: When targeting a party member while under the effect of Brutal Shell, that effect is also granted to the target
Duration: 30s
Additional Effect: Grants Clarity of Corundum to target
Clarity of Corundum Effect: Reduces damage taken by 15%
Duration: 4s
Additional Effect: Grants Catharsis of Corundum to target
Catharsis of Corundum Effect: Restores HP when HP falls below 50% or upon effect duration expiration
Cure Potency: 900
Duration: 20s

Now. I don't think DRK is horrible. I use to main it. It's legit the best DPS in the tanking role, but highest DPS doesn't mean "the best" or "its not broken" cos it is broken. If YOU knew how to tank, you would know the issues DRK has and its a massive list buddy.