Mard Geer Tartaros

{3}{b}: Put a thorne counter on target creature.
Creatures with thorne counters on them have
-1/-1 and can't untap unless their controller
pays 2 life.
At the beginning of your upkeep, you may look
at the top card of your library. If it's a demon creature card, reveal it and transform Mard Geer
Tartaros.