Grr, this card is OP. Problem with the counters is that they are very situational and not really useful against decks without antimatter.
Ok, enough raging, I get to my question: Do 2 antimatters cancel each other out? The wording (Creature heals you instead of attacks) seems to suggest otherwise, but a couple of posts on this thread suggest that they do. I'd test it but I have to go, so a definitive answer would be appreciated - thanks