One of the most powerful angels ever created, Alexiel rebelled against against God due to the corrupt practices occuring in Heaven. She was born from Adam Kadmon to love God, but she could not deny her love for her twin brother, Rosiel. As punishment for her actions, she is doomed to an endlessless cycle of reincartions into be miserable lives, each of which ends in a tragic death.
Her current incarnation is Mudo Setsuna, a human who is in love with his own sister, and is awakened as the Saviour. Setsuna therefore has access to all of Alexiel's powers.
Beautiful cosplay! I found this in Deviant Art and the cosplayer's name is Etaru. You can see more of her cosplays and model pictures here. Thank you for sharing this with us and thanks to Idolatry Studios for the wonderful photography!