There is a ritual...a dark dark ritual.. involving a pure bliss angel..they think you are this angel.. The ritual states that if said pure Angle mates/marries to a dark entity such as a demon..and births a dark unholy Angle... Boy or girl doesn't matter the gender of the angel...the ritual will be the same...in this case **you** are a boy .. and your brothers only want to protect you from **him** **Your the chosen one**