Fabula Nova Crystallis is a subseries within the Final Fantasy franchise, developed by Square Enix. It consists of several interconnected games that share a common mythos and thematic elements, focusing on crystals and their significance in the world. The main titles include Final Fantasy XIII, Final Fantasy XIII-2, and Lightning Returns: Final Fantasy XIII. The narrative explores themes of fate, sacrifice, and the struggle against oppressive forces. Each game features unique characters, such as Lightning and Snow, and distinct gameplay mechanics, while maintaining a cohesive storyline that delves into the lore of the Crystallis universe.