Quest for Wintertide

Whenever a creature an opponent controls does
not untap during its controllers untap step, put a
frost counter on it. When a creature untaps,
remove all frost counters from it. Whenever a creature has 3 or more frost counters on it
during your upkeep, put a quest counter on
Quest for Wintertide.
At the beginning of each end step, if there are 3
or more quest counters on Quest for Wintertide,
destroy target creature with a frost counter on it.