text: He chases the bear up onto a mountain and kills it . The Spirits , represented by Sitka 's spirit in the form of a bald eagle transforms Kenai into a bear after the dead bear 's body disappears .
simplified: After a bear takes the life of Sitka , the oldest brother , the impulsive youngest brother Kenai kills the bear in revenge , only to be changed into a bear himself by the Great Spirits .