Nikya of the Old Ways is a rare Legendary Creature — Centaur Druid card from Ravnica Allegiance (RNA), collector number 193. Current market price: $0.33 (foil $0.87), 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.