Will, Scion of Peace is a mythic Legendary Creature — Human Wizard card from Wilds of Eldraine (WOE), collector number 302. Current market price: $1.46 (foil $3.18), TCGplayer market prices via Scryfall.
Vigilance {T}: Spells you cast this turn that are white and/or blue cost {X} less to cast, where X is the amount of life you gained this turn. Activate only as a sorcery.