Ys vs Trails in the Sky Alternative Saga is a dynamic crossover that brings together characters from two renowned universes, Ys and The Legend of Heroes. Legendary adventurer Adol Christin, his faithful companion Dogi, and other heroes from the franchise find themselves caught up in mysterious events that transport them to the enigmatic land of Xanadu. Simultaneously, Estelle Bright, Joshua Bright, and their companions from Liberl are transported to this world. Here, they must battle each other in intense duels to uncover the secret of their journey and find a way to return home, all the while confronting a powerful being known as the Demiurge.