Hmm... interesting effect, I have a special place in my heart for cards that use your opponent's strength against himself (see two of my Armory cards for proof of that, hehe). But I think this deserves a cooler name, and while its effect is similar in principle to Antimatter, it almost seems like a Darkness card. Especially since most Darkness creatures have low stats. I can even see this being a creature with a one-time ability, like Deja Vu or Lycanthrope.
Those are my gut reactions, take or don't as you please!