Deep!!

There are angels in this world who don’t even have the right to be called ‘Angel’

Simply because their body lacks some of the parts that a proper angel is supposed to have…
Simple because their eyes are red
Simply because they are children born out of the love between two angels
Simply because they had the misfortune of being born into this world of ours…

And [(you) spoke] ‘thus has this world become a thing perfect…’

-Raziel (Angel Sanctuary -Act. 7 “Rabbit Hunt”)

These children were also called I-Child or “rabbit” because of their red eyes. I-Children are kids who were born by angelic parent. Yet in the heaven, the love between two angels were consider as a taboo and when they get caught, they will be punished to death. They don’t have part what most angel have like two angelic wings and the ideal or beautiful figure. Raziel is an I-Child and he was in brutal experiment designed by the Angel as a subject. Until, Zaphike saved him and became his mentor. Raziel soon became an angel volunteer investigation squads; thus, he went to the lower level of heaven. There, he found his kind and he wished to help him them because they looked miserable and not well. He asked the High Council in heaven, Sevothtarte, to help these I-Child. Sevothtarte offer the help, yet his offer was compromised.