Rise of Mana

The game opens with a battle between the respective Champions of Light and Darkness in front of the Mana Tree. While they are fighting near a Mana waterfall, they are swept by it into the mortal world. There, their power is drastically diminished and their existence is threatened. The two decide to make a temporary alliance, sharing a body until they can find their way back to the spirit world. During their journey, they become the protectors of a local village. (wiki)