Lier, Disciple of the Drowned is a mythic Legendary Creature — Human Wizard card from Innistrad: Midnight Hunt (MID), collector number 313. Current market price: $2.52 (foil $3.86), 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.