Alright, So during the preview I tried this skill and it was great, I mean, I did 40-60 damage both hits to achieve around 80-120 damage with the skill PLUS 75 armor ignoring damage to each adjacent foe (35 damage twice because it's a dual attack). That's pretty nice, just all around good...
But imagine 6 assassins using that skill all at the same time on a group of enemies. That is a 450 damage AOE spike. You can then recharge the skill with Moebius Strike and finish off anything that managed to survive. How insane is that? With a proper build you can chain up to it in seconds with energy to spare.
Descriptions for your convenience:
Death Blossom: Must follow an off-hand attack. If it hits, Death Blossom strikes for +15-35 damage against target foe and all adjacent foes take 15-35 damage.
Moebius Strike: Must follow a Dual Attack. If it hits, Moebius Strike strikes for +10-30 damage. If you strike a foe whose Health is below 50%, all your other attack skills are recharged. This is an elite skill.
EDIT: Actually, it will be even better with 16 Dagger Mastery. Also, I have to note that the Assassins will have to attack several different targets in the group, because if the foe dies in between hits, the second hit will not trigger the AOE damage, and probably, the attack damage from all of them at once doing a dual attack would kill a single enemy too fast and lose up to half the AOE spike damage.