OP bases their DRK design too much on the mechanics used by WAR. That's not a path I'd recomend taking because Wrath was designed to work in tandem with Defiance.

On a personal level I'd like to see DRK take up a big sword again like in ages past. XI's iteraction with scythe felt too awkward. MRD's base animations don't really allow for it unless OP intends the job to use a G-axe like MRD and WAR do.
Quote Originally Posted by Leiron View Post
lv 30 Dark Blade: Reduces Enmity generated by your abilities by 75%. Increases damage dealt by 40%. Replaces your axe with a greatsword. (RIFT uses the weapon replacement with Harbinger.)
As Kitru said, you'd need to create animations and models for every axe in the game. I don't think thats a good road to take. And I agree that if you wanted a DPS job to branch off a tank class all you'd need to do is set the job crystal to remove the Increased Enmity tags on abilities that have them.
lv 35 Creeping Shadows: Delivers an attack with a potency of 120 on up to 5 targets. Additional effect: DoT effect for 35 potency, lasts 30 seconds. Tp cost of 80
Up the TP cost, remove the DoT. This should be semi-spammable when AoE is called for like Doom Spike.
No idea what the rest would be
From a really old suggestion I made for DRK:
30 Dark Slash: Sacrifice HP to attack your opponent with a heavy slash, dealing physical damage and additional dark damage.
35 Umbral Symbiosis: Lowers target's Attack and Magic Attack by 3% and increases your Attack and Magic Attack by 3%. Costs 200 MP.
40 Night Slash: Drains TP from up to three targets in front of you. 400 MP cost. 20 second cooldown.
45 Asphyxiate: Interrupts spell-casting. 20-yalm range. 90 second cooldown.
50 Last Resort: Your next three weapon skills consume HP in addition to their normal costs for additional darkness damage.