Dark Mind (magic only): 60s cd.

Reprisal (lower target dmg 10% 5s): 60s cd.

Anticipation (parry rate +30%): 60s cd.

Rampart: 90s cd.

Shadow Wall: 180s cd.

Convalescence (heal +20%): 120s cd.

Effectively, DRK only has Rampart and Shadow Wall for physical dmg mitigation which both have long recast time. We only get The Blackest Night at 70.
So, if you're running sub-70 dungeons with a DRK, please understand the above.