Vermillion Bird Reborn!! EEWC

What happens when the greatest of the devine 4 spiritual beasts the the Vermillion Bird falls ill. what kind of illness could affect someone with such power. when she finds out Humans can also have this illness she cant comprehend. The only thing she is sure of is that everything started the day she met the handsome human boy with one purple eye and one blue. Can she find the cure? Who is this strange boy and why does he seem to be the key.