Whenever you cast or copy an instant or sorcery spell, tap target creature or artifact and put an Ice Counter on it. As long as a permanent has an Ice Counter on it, it cannot untap during its controllers untap step.

Remove any number of Ice Counters from permanents on the battlefield: search your library for an instant or sorcery card whose mana value is less than or equal to the number of Ice Counters you removed this way. Add that card to your hand then shuffle your library.