Ever since his half-brother's appearance in the banquet hall, Dante has been feeling a little on the edge. When talking to the other nobles, his eyes still vigilantly scan the crowd for red eyes and brown hair.
His half-brother is alive which means the body that was found years ago did not belong to him. To Dante, this also had another meaning. His half-brother faked his death and disappeared from the asterian empire after their mothers' deaths.
Judging by the quality of his tailcoat, his glowing skin and how he blended within the nobles, it appears his half-brother's life was good without the duchy.
Should he be happy? Dante did not know as he did not exactly have a relationship with his half-brother. Their mothers clearly hated each other and their father was of no help. Having a brotherly relationship will make things complicated, thus Dante ignored his half-brother throughout his childhood.