In Norse mythology Kara is one of the Valkyries who are also known as swan maidens or wish maidens. Legend says that if you can capture and hold a swan maiden or her feathered cloak, you can extract a wish from her.
The Valkyries are warlike women who are often depicted on horseback, armed with spears and led by the goddess Freya. They hover over the battlefield choosing who will be slain, before accompanying them to Valhalla.
The Valkyries are also messengers of the Norse god Odin, and when they ride forth on their errands, their armor causes the strange flickering light that we know as Aurora Borealis or Northern Lights.