[MunchkinMan]

The Mate is a separate Monster which just so happens to continually duplicate another Monster in the combat. That's why we have ruled in the past that any card that would remove one Monster played to remove a Monster that has a Mate should be used to remove the Mate, for simplicity's sake. In fact, any cards that can be played on a Monster should be played on the original. I know that there are similar cards to Mate which actually do something a little different, so in those cases, you may want to keep the duplicate and not the original (e.g., Mommy creates a more powerful copy). But, I can't see too many scenarios where you might want to use Annihilation or other Monster removal cards in that way, and no, that was not an invitation for others to provide me such scenarios.