Absolute Zero

Whenever a creature you control deals combat
damage to an opponent, tap and detain target permanent they control. If a snowpermanent
entered the battlefield this turn, it does not untap during their next untap phase. (Until your next
turn, those permanents can't attack or block and their activated abilities can't be activated.)
At the beginning of an opponent's upkeep, if they control six or more permanents and control no untapped permanents, they lose the game.