Board Thread:Legitimate Canon Questions/@comment-13895380-20170114165006/@comment-10123851-20170911155930

Just throwing my two cents in here.

The difference between Peter, Deuc and even Kate, and Sebastian is that the former are people. Deeply flawed and sometimes terrible people, but still human beings. And Peter still has love for his family.

Sebastian on the other hand is soulless, hollow. Fundamentally lacking humanity, even willing to kill his own sister.

If the form you take is a reflection of who you are. Than it's no wonder he's more extreme than any we've yet seen.