For the purpose of this ad, i will be calling him Ed. Now Ed here is open species, although Vampire would make the most sense given his relationship with Sol, and the plot i have in mind, but any other species would work just as well with a little more shifting around.
Ed here had a pretty hot and passionate relationship with Sol. One of the few people/vampires if you desire to go down that route, who agrees with him being an elder/advisor given he is a turned vampire. He has always admired him, and always respected him. He has seen great things for his future.
How and when Sol and Ed started their relationship is open, i had an idea of perhaps Ed working for Sol and either Shiver or Fortune and that was how their relationship started. They would have dated for a couple of years, the pair of them were serious, or, at least Ed thought they were serious. Their relationship came to an end a couple of months ago. It was a healthy split. Or, so Sol thought at least. The truth of the matter is Ed has been stewing over it. He had loved Sol, worshiped the ground the other vampire walked on. He was obsessive and in his own way mildly manipulative. He had a life planned for them and it did not include them ending things.
Ed will still work at either Shiver or Fortune, would still see Sol virtually every day. Ed had hoped that he would be able to win Sol back and when he finds out that he has started a new relationship with the Kings son he is beyond angry. He wants nothing more than for Corbin to die so that Sol will return to him. And has made more than one attempt on the other vampires life, not that anyone is aware that it is Ed.
Basically this guy, isn't the good guy he spent pretending to be around other people. Even with Sol there were many manipulative tendencies, small jibes directed at him, and he is going to do everything he has to in order to get him back. He plans to cause as much chaos until he has what he wants, one way or the other.