Natsuki

An angel who was banished from Celestia on false claims for conspiracy with demons. 

She grew up in a shaky household, while her parents wore "masks" in public, in their home, they neglected their two kids. An eldest, strong sense of justice & determined daughter and their courageous & rambunctious young son with their difference in age only being 3 years apart. That tiny gap didn't matter to the loving bond between the siblings, to them taking care of each other when the latter was sick to giving each other heartfelt gifts on their birthdays.

Vulcanus had summon her brother on a calm afternoon in the summer with the news of him going on brave, secret mission to the Netherworld to gather a certain treasure to give Celestia in the upper hand. Her brother had the biggest smile on his face that she hadn't seen in quite some time as he had thought that maybe after this, their parents would finally look their way. She didn't have the heart to tell him that that she gave up on such a thing eons ago but congratulated him nonetheless. 

He departed during the night of fall, reassuring her that he'd be back and that they'll have a better life. She was at lost for words against her brother's beaming happiness, making him swear that he'd come back in one piece. He swore with a tight hug and then... a goodbye that made her heart clench with worry.

That would be the last she saw of her brother, alive.

His body was left in the depths of hell, yet Vulcanus had discarded him like her brother was nothing when he discovered that the young man didn't even have the treasure on him. Flicking his wrist away like swatting a fly around him to get rid of his private affair behind the Seraph's back. The twisted archangel knew that the eldest sibling would make a ruckus, setting in motion of the eldest and her conspiracies for said treasure in hopes of claiming the high role of Seraph.

With no evidence to help her nor support, she was charged guilty and fell down to presumably meet the same fate as her beloved brother.

At least, that's what the archangel had believed in.