Doesn't seem to have been answered yet, so...

What happens to the stolen unit once the soul stealer attachment is destroyed? Does it stay under the DE player controll? Return to previously occupied zone? Vanish in a puff of pink vapor?

I wondered this when I saw the new restricted list too. It states in the FAQ that it is an ongoing effect and the Unit returns to the owner's control if destroyed.

I really dont see how this was ever a good card with Vaul's Unmaking ready to waste your 4 resources.

Ah, yes, I somehow missed it in the faq section, thanks.

Well, from the point of view of my mono chaos deck, it's still a rather powerful card, and you can always develop it if you're up against order. Destruction overall lacks means of countering it short of sacrificing the affected unit in response.

GrumpyStranger said:

What, Embers to Inferno not enough for you ?