Wonder of U

Stand - Once per match, if you control a Legendary Creature or Planeswalker, you may cast this card from your library or graveyard.

While you control Wonder of U, whenever an opponent plays a card that would target you or a permanent you control, place a Calamity counter on that opponent. During your end step, each Calamity counter deals half of that opponent's life total, rounded up.

"The flow of calamity makes no distinction between right or wrong."