Sebastian wasn't born a demon but grew up as one. He doesn't have a heart for anyone in the world after his mother died. He tried selling his soul for her but his father screwed him over. He lost his soul and his mother all in one. He hates everyone and makes it quite clear at first meeting. He is easily vexed and lives where ever his feet take him. He's a nomadic male and a smart one. He use to live with his mom in Oklahoma. Why Thanatos picked such a nice caring woman is a mystery to everyone. Once Thanatos was out of the picture Sebastian's mom saw some things about Sebastian she didn't like, but never pointed them out because she loved her son to death. Yeah poor choice in words. When Sebastian was eleven his mother died. She died in a mugging. Sebastian loved his mother to death, but that was when he lost all hope for humanity. His mother was just picking up groceries. Sebastian,ofcourse, murdered the man that mugged his mother. He also murdered the mans own mother. He didn't even care. When his father came to retrieve their souls he asked if he could trade his own for his mothers. Thanatos smiled and nodded. He had Sebastians mother right there, well atleast her ghostly body. Sebastian was speaking with her and she was very dissapointed in his actions. For murdering then giving away his soul. Thanatos took his mother away then laughed in Sebastians face. Your soul is mine forever~! That was the last time he'd ever spoken to his father. Little Sebastian carried on souless and sad through out all his years. Every year on his mother's birthday he would go to her grave and speak to her about all the sins he commited, since he could speak with the dead. When Sebastian was sixteen she stopped coming to the grave. Sebastian knows she hated hearing his sins, but he never thought she would give u. That's when he truly lost all hope in regaining himself.
Now, Sebastian never goes back to his mother's grave but stays as far away from that state as possible. He usually walks everywhere he goes. He acquired a blade when visiting old ruins in his travels. He calls his blade Chaos, because it always seems to cause Chaos. Whenever it's out or he has to use it against monsters. Sometimes he thinks his dad sends these monsters after him. He also thinks his dad sent him to the blade, but then again his dad stole everything from him. Why would he try to make up for it with blades and tasks? Seastian challenges a lot of people because he can fight really well. Where ever he goes someone always tries him. He's not very patient and usually takes matters into his own hands. By that I mean he will be cool one second than wailing on you another. He's never lost a fight before. He doesn't seem intimidating, but when his eyes turn red, you should be frightened. If you're not that will upset him, which will make him go twice as hard on you. He can't use his Chaos blade on you but I think you're better off with the blade. He still has powers over lots of dark things. Plus he has dark magic. H's a demon for crying out loud~! A heartless. When he's moved on to the next city or state, he's left behind a scent for monsters to track him. None of them ever get the best of him. He's heard many things in his travels about camps that train you for these monsters. He's been fighting them since he was eleven and probably is way more experienced then the eldest ones. He's thinking of one day going there just to show how good he is then leaving just like he always does. Maybe he'll pass by, but for now he continues his travels with Chaos and being a heartless and souless demon.