Vassalord.

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! But can Charley resist his own desperate cravings for blood? Find out as the devilish duo go up aginst a childlike vampire princess, a mysterious branch of the Unitarian Church...and one another.

(Source: Tokyopop)

Included one-shot:
Volume 2: Zoul Half