Christian is a well-spoken (can be regional, but must be articulate, fluent and clear... ), intelligent, but shy part-vampire who has offered to help the Fae Group, who are looking for a wizard who has been kidnapped by an evil Vampire Viscount. 

He has lived in isolation of others for many years, he is 20 years old and the forest the group are travelling through was once his home. He is overly formal when he speaks because he is uncertain of how to handle his encounter with Fae Royals. There is a warmth to him, but it is likely hidden under layers of uncertainty and apprehension of this particular social situation...slightly distant, but the lines are above show him at his most tender, with Princess Lilly (listed above), the character he finds the easiest to talk to. 

Christian desires to be 'friends' with the group, however, is wary of what they will think of him when they find out his true position and troubled past with Lewis' (the fae diplomat) home (Christian is part of the reason the forest was destroyed). It is unknown to the player early on in the game, but it is later revealed that he has a powerful position of power within the Underworld and is known as a 'Duke' and advisor to the King of Death...this is secondary to his performance and he actually finds it a little embarrassing, he is level headed and doesn't 'use' this title as it makes him feel awkward.  

Christian would not talk with a great deal of volume and his expressions would at times be a little muted. However, when speaking about his own feelings or in situations where the characters are truly upset, he would be able to communicate with warmth...he is very thoughtful and thinks about how his actions would be perceived. 

To add context Christian is the ‘Advocate’ personality type, despite his introverted nature, he wants to be a force for good in a world where he is not seen as such, he hopes that aiding the fae will demonstrate that he wants to help and not hinder their quest. https://www.16personalities.com/infj-personality