Jean-Claude was born in France in the 1700s. His parents sold him to a noble family so they could use him as their child's whipping boy. Jean-Claude was raised in the noble family's home and educated, but he still has the whip scars on his back. Jean-Claude became a vampire in France and quickly mastered his powers. He was naturally beautiful, even as a child, and his being undead makes him even more gorgeous. He has shoulder-length black hair and midnight blue eyes. His voice alone is seductive and he likes to wear V-neck shirts with lace down the front and on the sleeves. No matter what he wears or says though, he is very masculine. Jean-Claude has a crush on Anita Blake, the local vampire executioner. He constantly pursues her. He wants her to be both his lover and human servant.He also insultingly refers to her as "Little Animator".
He is vulnerable to sunlight, fire, and holy water but not Crosses which he blatantly gloats about, he even has a Cross-shaped scar on his chest. It's hinted at he killed his mother and father, Anita says to him
"I killed the things that gave me this scar"
"As did I" He responds.
Whether he's referring to the whip marks or the cross-shaped scar is unclear, but what is clear is his ruthlessness.
The story-arc "Guilty Pleasures" begins with Anita Blake being interviewed by William McCoy or "Willie" McCoy, who wants her to investigate a series of vampire murders, ironically Anita was already on this case and simply declined his offer. Shortly afterward, we see Anita lying in her stuffed animal filled bed trying to get some sleep amidst the chaos of being an animator, this sleep is of course interrupted...by a friend who wants her to go to a bachelorette party, she (half asleep) accepts. "Guilty Pleasures" as it's called is the only strip-club for females in "The District" or as humans say "Blood Square" or "Riverfront". The minute they arrive, they're greeted by Jean-Claude who seems to know Anita from somewhere..
Regardless, she grudgingly removes her cross necklace by request and goes to the show where Phillip or as Anita calls him a "Vampire Junkie" gets bitten, drained and thrown to the floor.
At this point, Anita leaves for the graveyard to investigate the string of vampire murders, she concludes that the murderers must have been ghouls and returns to Guilty Pleasures. When she returns, she has brief exchange of words with Jean-Claude and than go's inside, once inside..she meets Aubrey, a manly vampire womanizer, similar to Jean Claude who is seen with her friend Catherine wrapped around his arm, when Anita enters, he loses his interest in her and moves on-to Anita. Although he is similar to Jean, he comes closer to hypnotizing her with his charm more so than Jean-Claude ever could...but Anita resists and he attacks her.
Jean calls off the vampire and Jean and Anita go for a walk, he attempts to steal a sultry kiss but due to Anita's superior willpower fails.
Jean-Claude is a vampire, so he has many abilities. He is also a master vampire which means he is very powerful and has gained more powers than younger vampires. He is able to "cloud" human minds using his eyes and make them see illusions or move so quickly that the human thinks he used simple magic. He also has the usual vampire abilities: super strength, speed, smell, hearing, healing and flight. Many master vampires are able to call an animal and he is no exception, as he is capable of calling wolves and as an extension of that, werewolves. Jean-Claude is able to put "marks" on any human. Four marks and that human becomes his servant. A human servant resists most if not all of his vampire master's powers, but is always drawn to the vampire to help him if he calls. A vampire can only have one human servant at a time.
Jean-Claude is in theory immortal, but can still be killed by a stake through his heart, being exposed to sunlight for a long time, fire, a shotgun blast to his head or heart, or having his head severed as well as countless other methods. One special thing about Jean-Claude is his age is known to very few as he has the ability to disguise it, to make it very difficult for one to guess his true age, though obviously some who were there during his beginnings such as Asher and Belle Morte know the truth.
Jean-Claude's power levels increased exponentially when he bonded with Richard and Anita as part of the Triumvirate, becoming one, and has given him a mind-to-mind link with both of them and quite a lot of control over them. However, those powers which make Jean-Claude "unique" from your run-of-the-mill vampire are usually sexual in nature (which may explain why most of his clubs are strip clubs, or something of the like) as he is an incubus. Jean-Claude is a descendant of Belle Morte's line, but has reached such power levels that he became his own sourde de sang. He has the power to bond other vampires to himself through blood oaths, and cause a variety of other effects through sex, as it is what feeds him.
He is also required however, to feed off both his bloodlust and ardeur at least once a day to refrain from becoming weak, as weakness is not something he can allow to be seen as the Master of the City.
A power he possesses that can hardly be called vampiric in nature is just his intelligence, after centuries of life its almost impossible not to pick up a few things, and although most of his knowledge is related to vampire rituals and understanding of all the inner workings of their world and the Council, it has given him more plain gifts such as the ability to speak multiple languages including English, French and German.