Ys vs Trails in the Sky Alternative Saga is a crossover action game from Falcom that brings together characters from the Ys and Trails in the Sky series in an alternative, non-canon story.

Rather than a traditional RPG, it focuses on fast, arena-based battles where fighters use signature skills and abilities against each other. Fans of either series get to see beloved casts meet and clash in a story built purely for the crossover, with a large roster to master.