Klaus Demion

Klaus is a twin born to a marriage between two long-established families of demon hunters. Growing up, he was sickly and often overlooked in favor of his outgoing brother, Gunter. Klaus discovered his parents' secret dungeon where they captured and interrogated demons and took pity on a demon and soon fell in love, though unrequited at the time. When the boys were 18, Gunter and Klaus had a falling out which led to the destruction of a protective charm from demons on their manor. Klaus took this opportunity to make a deal with the demon and kill himself, sending his soul to Hell with the demon he fell in love with.

Klaus is now older (though dead), and has begun a relationship with Mara, the demon. They are in love. They love eachother very much. They work with eachother to overcome mental issues and are very good to eachother. Things are good. Do not hurt them or I will hurt you.