Alexis Arc: Heroes of the Three Kingdoms

It has been five years after demons invade the land of Eldeamor. To make things worse, the three kingdoms in the land: Auria in the northeast, Callista in the south, and Deminia in the northwest are having inner conflicts with each others. Even though they are related by blood, they have to make difficult decision on who they should help. Who will they choose? They have to save each others while not knowing the mysterious force at the bottom of the land's river...