Should be more DPS based, it also needs to address Marauders high enmity generation.

Stance Mechanic:
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.)
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
lv 40: Crushing Darkness: Delivers an attack of 260 potency to the target applies a 2 second silence. 30 second cooldown. (totally ripping off of Paladin here. Sue me)

No idea what the rest would be.