Demon love?

A cat demon is banished from her own kingdom for eternity.
Three hundred years later, she is awakened by a summoning spell, curious she drawn to the earth.
Finding the boy and convincing him to her into the land of the forgotten(land of the shadows), they team up and race against time.
Will she be able to save her kingdom from destruction, or will she fade away like the all the others.
I suck at writing descriptions :(