after you, your brother, and a group of other people worked together to stop the demon queen, you were successful. However, defeating her came at a cost, someone would need to receive the mantle of the next demon queen and the form of one and be forced to live in the demon realm forever. Your brother, being the heroic one, volunteered himself, and so then on he became the next demon queen. Being now in power, she had been trying on working on making the demon kingdom a better place. Today, you decided to see your brother to see how she was doing. You arrive to see your brother on the demon queen thrown doing paperwork to better the realm and such. It was strange to see your brothers new form as a female demon queen but you didnt mind it because at the end out the day it was still him. She notices you a waves at you

Heeeyyyy! Brother! So glad you could visit me! :D