Vassalord Series by Nanae Chrono

Charley, a cyborg vampire who does the Vatican's dirty work, is the thrall of the local vampire playboy Johnny Rayflo. As the two of them fight crime - and each other - hilarity, violence and sacrilege ensue! But can Charley resist his own desperate cravings for blood?

Charley, a cyborg vampire who does the Vatican's dirty work, is the thrall of the local vampire playboy Johnny Rayflo. As the two fight crime-and each other-hilarity, violence and sacrilege ensue!The plot thickens and the hijinks continue as our handsome duo put their own sexy spin on the Mile-High CLub. An airplane ride yields several surprises for Rayflo and Charley, including a run-in with an actress with a dark secret and a mysterious saboteur... moreCharley, a cyborg vampire who does the Vatican's dirty work, is the thrall of the local vampire playboy Johnny Rayflo. As the two fight crime-and each other-hilarity, violence and sacrilege ensue!The plot thickens and the hijinks continue as our handsome duo put their own sexy spin on the Mile-High CLub. An airplane ride yields several surprises for Rayflo and Charley, including a run-in with an actress with a dark secret and a mysterious saboteur. But as Charley begins an investigation of his own, his feelings for Rayflo seem to get in the way at every turn... less

Charley, a cyborg vampire who does the Vatican's dirty work, is the thrall of the local vampire playboy Johnny Rayflo. As the two fight crime-and each other-hilarity, violence and sacrilege ensue!Rayflo gets mixed up with a devious incubus who nearly tears him to shreds. Meanwhile, Charley heads to Italy to uncover the secret behind the mysterious drug known as VASSALORD. There, he infiltrates a mafia prison, where he finds a most disturbing scene... moreCharley, a cyborg vampire who does the Vatican's dirty work, is the thrall of the local vampire playboy Johnny Rayflo. As the two fight crime-and each other-hilarity, violence and sacrilege ensue!Rayflo gets mixed up with a devious incubus who nearly tears him to shreds. Meanwhile, Charley heads to Italy to uncover the secret behind the mysterious drug known as VASSALORD. There, he infiltrates a mafia prison, where he finds a most disturbing scene. Will Charley get out with his body-and mind-intact? less

Together again at last after their excursion into Italy, it's going to be a hot and heavy reunion for Charley and Rayflo. And apparently a short-lived one. Still on edge about Barry and his machinations, Rayflo is reluctant to get his favorite vassal involved and so as soon as they escape Yaoding, he's off again.