The Animated Movie "Brother Bears: Back to Earth"

about

A mysterious alien, Avi, arrives in Pine Hill and befriends Brixni. He gradually learns that the alien's people, the Ryots, come from earth. Millions of years ago, the highly advanced Riyot civilization thrived at the expense of nature. Eventually they had to leave their home planet. When Avi leads Brixney to the ancient relics of his people, they are both attacked by a human army wielding a variety of high-tech weapons. For what purpose did Avi return to earth? Will it be possible to protect the home planet this time?