Muse Seeker is a uncommon Creature — Elf Wizard card from Secrets of Strixhaven (SOS), collector number 60. Current market price: $0.22 (foil $0.30), TCGplayer market prices via Scryfall.
Opus — Whenever you cast an instant or sorcery spell, draw a card. Then discard a card unless five or more mana was spent to cast that spell.