Most of the time there aren't going to be more than maybe two or three creatures out, so this is usually going to take a quality creature, at least in the early game. I think it should have a much higher cost, but I do like the idea of stealing a creature. I'd propose something along the cost of Sky Blitz, where it costs about 9//8 and drains remaining entropy quanta. That might be going a bit far, but 5//4 is way too cheap for sure. You might be able to get away with something that cheap if it also had some sort of negative effect on the creature itself, like giving it -1/-1 or poisoning it.
Agree with draining all remaining quanta. Imagine a deck with 6 of these..
-Unless I get your strongest creature I will play one more.
Maybe if the creature that gets stolen also get antimattered?
