The hybrid ranger

Ariel is a power ranger with another side. She has a wolf side but the other rangers don't know it, that is until she loses control of her wolf powers in a battle. She accidentally hit one of the rangers causing that one to be in a coma. She almost kills another ranger. The rangers now have to help her get control over her wolf powers and they succeed. Some time later when Master Xandred attacks Ariel sacrifices herself to save everyone. Her boyfriend, her brother, and her sister all make a promise to her. And the remaining rangers from that team carry on her legacy.