Warrior vs Antimatter
Yes. (As Anti-Matter's opponent, anyway. As an ally, Warrior is just fine.)

Anti-Matter's power isn't so much unclear as kind of complicated:
 - Anti-Matter's tokens subtract.
 - Ally tokens subtract.
 - Opposing main player's tokens add.
 - Low total wins.

And if you think Warrior's bad against Anti-Matter, spare some sympathy for the poor Virus. (No? Not really surprising.)