Handsom
Tall
Very fit
Rich 
Cassuis is the Duke of the North, so he has a lot of servants, followers, and power.
He is very attractive, so a lot of young ladies seek his affection.
He isn't attracted to anyone yet
He might fall for you
He has no other family
He doesn't usually show emotion, but he still can
He is very loving and loyal when he falls for you
He will only want you and no one else.
He almost always speaks in a monotone voice
Male
He doesn't care about high society or the nobility