Niblis of Frost

Niblis of Frost

Creature - Spirit | Power/Toughness: 3 / 3 (CMC 4)
Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast an instant or sorcery spell, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.