I think that I'd like this Shadow better if it was a targeted attack on something. There are two reasons for this. First, it takes away the feeling that this is a pet that you have to somehow babysit. Second, if the enmity transferred to you, you could just throw it on something that has just spawned and have your Shadow escort it back to the group. It would also make sense if this whole thing was snappier. The potency value of the ability is offset by any delays spent summoning as well as the potency value of the 50 blood cost.

I'm not sure why this thing has its own UI gauge, either. It would make sense of Edge of Shadow or Flood of Shadow actually interacted with it to extend the duration, or alternatively, if they made your Shadow throw in extra oGCD uses of Edge for additional hits.