Echocasting Symposium is a mythic Sorcery — Lesson card from Secrets of Strixhaven Promos (PSOS), collector number 44p. Current market price: $5.76 (foil $7.14), TCGplayer market prices via Scryfall.
Target player creates a token that's a copy of target creature you control. Paradigm (Then exile this spell. After you first resolve a spell with this name, you may cast a copy of it from exile without paying its mana cost at the beginning of each of your first main phases.)