Nita, Forum Conciliator is a rare Legendary Creature — Human Advisor card from Secrets of Strixhaven Promos (PSOS), collector number 206p. Current market price: $0.18 (foil $0.30), TCGplayer market prices via Scryfall.
Whenever you cast a spell you don't own, put a +1/+1 counter on each creature you control. {2}, Sacrifice another creature: Exile target instant or sorcery card from an opponent's graveyard. You may cast it this turn, and mana of any type can be spent to cast that spell. If that spell would be put into a graveyard, exile it instead. Activate only as a sorcery.