He's a lively and mischievous character, typical of a middle school boy his age. In combat situations, he shows a calm and serious demeanor, but when the situation is clearly in his favor, he also displays a sense of ease by cracking jokes and acting relaxed.
That said, despite this composure, he's still young. When he sees Ethan break down after losing his father, he's deeply shaken and ends up vomiting from the shock. He also becomes visibly withdrawn and distressed when told that Hyeonho was put in danger because of him, showing that his mental fortitude isn't especially strong.
While he's initially well-mannered and friendly, Sean develops more of an edge after experiencing loss and guilt as a result of various failures.
(Source: Dead Mansion Wiki)
Content compiled by AnimeList.moe from publicly available sources.
