Lothaire's Links
Lothaire sees Calhoun as his arch nemesis, as he is not only a threat to Master Vasile, but also because Calhoun murdered him as a human twelve years ago -- which is actually a lie told by Vasile to better keep his loyalty. He usually gets painful flashes of memory whenever Calhoun fights him. As a human, Trey was Calhoun's best friend. He cared deeply about him, and did whatever was necessary to keep him safe.
Calhoun only sees Lothaire as an annoyance and an obstacle in front of his real target, Vasile Fane. He has no idea about Lothaire's real identity. When Lothaire, previously Trey Montel, was human, Calhoun saw him as his best friend. He cared and incredible amount about him, and became quite bitter after his death. He also carried minor feelings for him, but never said anything.
Vasile is Lothaire's superior and nothing more. He will do whatever his master tells him to do without question. He does not know that Vasile is the one who killed him, as his master tells him that Calhoun MacKenzie did; and that he "saved him from death" by turning him into a vampire.
Vasile sees Lothaire as nothing more than a tool for his bidding. He still has not revealed to Calhoun MacKenzie that Lothaire is his old partner, Trey Montel for his own amusement.