Throne of Eldraine is a rare Legendary Artifact card from Wilds of Eldraine Commander (WOC), collector number 28. Current market price: $31.16 (foil $39.81), TCGplayer market prices via Scryfall.
As Throne of Eldraine enters, choose a color. {T}: Add four mana of the chosen color. Spend this mana only to cast monocolored spells of that color. {3}, {T}: Draw two cards. Spend only mana of the chosen color to activate this ability.