Megrim

Target player loses 4 life and you gain 4 life.

Whenever this creature attacks, you may tap target creature.

Enchant creature Enchanted creature gets +2/+1.

You may tap or untap target artifact, creature, or land.

Enchant creature Enchanted creature gets +1/+2.

You and target opponent each flip a coin. Mana Clash deals 1 damage to each player whose coin comes up tails. Repeat this process until both players' coins come up heads on the same flip.

Defender (This creature can't attack.)