Nikya of the Old Ways is a rare Legendary Creature — Centaur Druid card from Ravnica Allegiance Promos (PRNA), collector number 193s. Current market price: — (foil $1.11), TCGplayer market prices via Scryfall.
You can't cast noncreature spells. Whenever you tap a land for mana, add one mana of any type that land produced.