ragged playmat mtg card Puggernaut - Andrea Radeck - Creature Collection color printed and officially licensed Double GFRGTFHYT Playmat for MTG Cards

I can see it being a sweet card in a Kaali (sp?) deck

Once a creature you control has become blocked by a single creature, giving it menace by turning it face down somehow won't cause it to become unblocked

Mathas forces your opponents to work together if they want that tasty card draw, by picking off the creatures you put targets on

Without it being able to grab spells like Mnemonic Wall, perhaps we would see a transformation to a more creature-based flicker strategy

As this ability resolves, the battle's controller exiles it then casts the back face from exile without paying its mana costand there won't be a mana cost, so that part's easy