Soul-Strike Technique is a common Enchantment — Aura card from Modern Horizons (MH1), collector number 30. Current market price: $0.11 (foil $0.11), TCGplayer market prices via Scryfall.
Enchant creature Enchanted creature gets +1/+1 and has vigilance. When enchanted creature dies, manifest the top card of your library. (Put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)