Sebastian is an introverted character who tends to keep to himself in his basement, working as a freelance programmer. He often feels underappreciated by his mother, Robin, and step-father, Demetrius, who tend to pay more attention to his half-sister Maru, meaning he often comes across as unfriendly to new people. However, the person he hangs out with and trusts the most is his best friend Sam, despite having to babysit him a lot whenever he does anything crazy. Sebastian is the typical "bad boy" type, owning a motorbike, has ear piercings and even smokes. 

For Sebastian, I want to avoid the stereotypical goth/emo voice, whilst he he slightly soft spoken, he can raise his voice at times. I imagine a more deepish voice for this character, not TOO deep though. 

This is a character who will shout occasionally.