I like that ability, but it's UP when compared to other nymphs. The ability isn't that strong, considering your creature has to die for the ability to take affect, so there's no need to compensate by having low attack. I would personally suggest making it a different creature so you could lower the cost, but if you want it to be a nymph then imo it needs more attack.
Also, I agree with Jyiber; this doesn't fit Aether very well. It seems more like a death/life ability to me.