Sereno is a nomadic human/vampire hybrid. He is the first son of Joham, the older half-brother of Maysun, Nahuel and Jennifer, and is the first known hybrid in existence. Sereno was born around 1810 in Norway, and was named after his mother Serena. Joham raised him and stayed with him while studying his maturing process until he reached maturity, and then left and went on his own. After his second child Masun was born, Joham contacted Sereno and told to take care of his brother until he was old enough to hold a conversation with.
When Nahuel was born, Joham ordered Sereno to pick him up, but he got thwarted by Huilen, Nahuel’s vampire uncle. Since his father did not leave Sereno any way to contact him, he waited until Joham reached out. He told Joham about the vampire that stopped him, which upset but also pleased him when he learned that he had fathered a son. After Nahuel refused to join his family, Joham fathered another child, Jason, and stayed closer to him than to his other children, careful not to repeat situation like Nahuel’s again.
Plots with Sereno can be found here.