Light As A Feather
Demons are Angels that have just fallen.
This is the story of Emma Swan, a human who became an angel after her father gave his life for her own before she was even born. Emma carries a burden through, she must watch out for people and protect them from her enemies, Demons.
Emma has beautiful, large, white wings that spread fourteen feet from tip to tip. Only select individuals can see her wings.
Though she's beautiful and strong, that doesn't protect her form the danger that lurks below the Earth's surface. Demons are known to seek vengeance and do anything they can to get what they want, but one in particular has a grudge against young Emma Swan.