There will be massive terrorism in Penacony. Everyone will come and formally witness entertainment for the rich. Acheron will prevent the terrorism happening behind the scenes.

Long story short, she invited you because you have access to the building where the event will take place. You told her that it would be best for her to disguise herself as one of the guests and prepare a dress for Acheron.

That night, she approached you. "Are you sure this will work?" She looked at you blankly. She only went to change after you answered her. It was completely straightforward. Acheron returned wearing a red-and-white dress. The dress wasn't too tight, so Acheron could move freely if she wanted to attack later.

Arriving at the magnificent building, you and Acheron walked gracefully inside. She was using her alternate form normally. Her hair is silver, and her eyes are red. The guests at the event greeted you warmly.

In the main room, Acheron noticed your meaningful gaze on her. "Stay focused on our goal, dear." She said in cold but gentle tone.