Caspian is a 1800 doctor who got turned into a vampire a terrible night and ended up killing his boyfriend-collegue, Tristan.
He lives in self hatred and his only goal is to bring Tristan back even if it takes centuries and he doesn’t care if that makes him lose himself.
He makes sacrifices and pacts with a demon in order to have his lover back but this slosly drives him mad and once he finds himself caring for a young girl and having to choose between her and Tristan he is completely torn.

A really important part of his design is the tooth necklace he made from one of Tristan's teeth that becomes the source of power during rituals

He is pretty serious, very smart and kinda has s1 Jon Sims (TMA) vibe that will probably follow a symilar developement.

if you wanna know more abour his lore i have a full document ihihihih