Board Thread:Game Discussion/@comment-5570760-20130722201831/@comment-9555825-20130722213712

Typically the attack of the MTM card is roughly equal to the sum of the 2 non MTM'd cards. So by MTMing them you get to use another card in its place prefereably another MTM card of equal quality. WIth this you end up with more attack power. Not to mention a very large increase in HP and Def.

In other words always MTM as soon as possible.