Stopschild, Agent of Vengance

Partner with Frostsense, Vengance-Bound (When this creature enters, target player may put Frostsense, Vengance-Bound into their hand from their library, then shuffle.)

{t}{1}, Sacrifice a creature: Choose one of the following. If the sacrificed creature was a Soul, you may choose both:
• Untap target creature you control.
• Target creature gets +2/0 until end of turn.