Why don't you add a little side effect? Something simple, like
Gain life equal to target creature attack, then set it to 0.
So the cost of the card is more balanced (i think).
This will cause the owner of an antimattered creature to take damage, though. But i think versatility is a good thing!
Nice card, anyway, i like it!
![Wink ;)](https://elementscommunity.org/forum/Smileys/solosmileys/wink.gif)