As many have said, all DRK need is a few changes:

1 - Change crossclass to Lancer. (Fixed TP issue)
2 - Change Reprisal to 20s CD / 30s Duration, Does not Require Parrying.
3 - Change Delirium to same as Monk Buff
4 - Dark Dance Dark Arts effect to increase Parry by even more.
5 - Blood Price to trigger on damage taken.
6 - Make Grit let DRKs Parry Magic attacks. (I know I`m dreaming)