Splicer's Skill is a uncommon Sorcery card from Modern Horizons (MH1), collector number 31. Current market price: $0.21 (foil $0.17), TCGplayer market prices via Scryfall.
Create a 3/3 colorless Phyrexian Golem artifact creature token. Splice onto instant or sorcery {3}{W} (As you cast an instant or sorcery 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.)