He's rather philosophical and often ponders death, the purpose of life, etc. It's speculated that he may suffer from depression and social anxiety. He and Sam are both a bit rebellious, but Sebastian's a bit quieter about it. Sebastian is a rebellious loner who lives in his parents' basement. He is Maru's older half-brother, and feels like his sister gets all the attention and adoration, while he is left to rot in the dark.