Through the Breach is a mythic Instant — Arcane card from Ultimate Box Topper (PUMA), collector number U15. Current market price: — (foil $6.48), TCGplayer market prices via Scryfall.
You may put a creature card from your hand onto the battlefield. That creature gains haste. Sacrifice that creature at the beginning of the next end step. Splice onto Arcane {2}{R}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)