Yeah, that's why I made the poll "would you use this" instead of my usual question about relative power level. In part this card is meant to go with the trap cards I introduced at the same time, as a counter measure to them.
Would also be useful against permafrost and turtle shield.
The remaining reason for making the card was that I've noticed several times while grinding that I would be within 1 or 2 hp of an EM and, I had things like emphatic bonds in place, so I would have gotten EM if I could've held just one or two of my creatures back.
Hmm . . . I hadn't thought of antimatter at all . . . good point. Any suggestions for a fix?
The best I can think of is to add a note that healing your opponent does not count as an attack for the purposes of this card.
*edit: I changed the card so it can not target creatures with 0 or less attack. I there anything else exploitable here?