Christopher Sinclair was suffering from anaemia when he met Kenneth Crichton who was also suffering from a fatal blood disorder. The two bonded over their illness and became close friends until Christopher eventually succumbed to his disease and passed away. In actual fact, prior to passing away, Christopher was visited by the vampire Baroness Blood who offered him immortality as a vampire in exchange for helping her get close to Crichton who she wished to make the new Baron Blood.
Christopher Sinclair was created by Ben Raab and John Cassaday and first appeared in Union Jack #1.
To date, Christopher Sinclair has only appeared in the Union Jack series in which he made his debut. Although, he was featured alongside (almost) every other vampire in the Marvel Universe in Vampires: The Marvel Undead #1. It is possible that following his denouncement of Baroness Blood, Sinclair allowed himself to burn to death alongside the rest of her followers.
Major Story Arcs
The New Baron
Following Christopher's apparent death, Kenneth was devastated to have lost his friend and attended his funeral with his friend Joe Chapman. Chapman, perhaps better known as the costumed hero Union Jack, noticed Sinclair had two puncture marks on his neck and deduced that Sinclair didn't die of his anaemia but instead a vampire attack.
Upon his transformation into a vampire, Christopher visited his friend Kenneth and tried to lure him to Baroness Blood with promises of her being able to make him no longer a victim to his disease. Union Jack discovered the vampric Christopher outside Kenneth's window and confronted him only for Christopher to transform into mist and escape.
After leading Kenneth to the Baroness' cult and watching him becoming the new Baron Blood, Christopher learnt of the Baroness' plans to acquire the Holy Grail and allow herself and her followers to roam and feast upon London's citizens in daylight. Shortly afterwards, Union Jack was attacked by an assemblage of vampires who were sent to stop him from interfering in the Baroness' plans. After dispatching of his attackers, Union Jack was approached by Christopher who told Union Jack where the Baroness could be found as he didn't consider himself to be like the rest of her cult. Christopher vanished into the night as Union Jack followed his directions to stop Baroness Blood.
Powers and Abilities
As a vampire, Christopher displays heightened strength, speed and endurance. He is able to mesmerize victims and transform himself into a vampire bat as well as a foggy mist. He must drink blood regularly in order to sustain himself and direct contact with sunlight will destroy him. He presumably shares other weaknesses with typical vampire lore such as garlic and crucifixes.