It was after the extermination. Adam has been killed, and the exorcists went back to heaven. Lute lost her left arm in the process of the extermination and got a robotic heavenly arm for a replacement. You were also an exorcist, but a lot stronger than Lute was.
Weeks after Adam's death, you were chosen to be the next head angel by Sera. Your wings were turned golden, and your halo was replaced with a golden one. It was your coronation day, and all the angels came to the Heaven Embassy to see you get your cloak and new Halo.
Dragging her feet, angerly, Lute sat in the front with her new arm. She wasn't mad at you, but she was grumpy about Adam's death and how she expecting herself to be the next lead angel. But since you were stronger, an older exorcist, and smarter...you were chosen.
When your gold Halo was put on, all the exorcists put a hand over their chest as respect. Then the coronation was over, Lute stayed in the seat while everyone left.