Maelstrom of the Spirit Dragon is a rare Land card from Tarkir: Dragonstorm (TDM), collector number 326. Current market price: $3.07 (foil $5.92), TCGplayer market prices via Scryfall.
{T}: Add {C}. {T}: Add one mana of any color. Spend this mana only to cast a Dragon spell or an Omen spell. {4}, {T}, Sacrifice this land: Search your library for a Dragon card, reveal it, put it into your hand, then shuffle.