One of the companions you can adventure with in Hogwarts Legacy is Sebastian Sallow. He entered Hogwarts when he was 11, belongs to Slytherin house, and you can befriend him to gain access to special missions and chances.
Sebastian is a charming, gregarious, and outgoing student who doesn't mind getting into mischief. This little Slytherin has a sinister secret, however. Sebastian is determined to help his twin sister Anne, who is afflicted with an unknown curse, even if it means indulging in dark magic.
Solomon Sallow, Sebastian and Anne's uncle, cared for them after their parents died. Their house was attacked by Ranrok and his followers as they began their fourth year at Hogwarts, leaving Anne injured and cursed. The curse on Anne caused a terrible, incapacitating illness that left her in excruciating pain and prevented her from returning to Hogwarts.
