Lier, Disciple of the Drowned is a mythic Legendary Creature — Human Wizard card from Innistrad: Midnight Hunt Promos (PMID), collector number 59p. Current market price: $1.28 (foil $3.51), TCGplayer market prices via Scryfall.
Spells can't be countered. Each instant and sorcery card in your graveyard has flashback. The flashback cost is equal to that card's mana cost.