I think that I read this in the late 90s to the early 2000s. It might have been on Keenspot at the time, as I read a lot of comics there. More of a western art-style, not anime, more realistic than cartoony, in English, full-page entries with panels. The protagonist was a Caucasian male teenager, I want to say with light brown hair. Early in the comic, he's possessed by the girl (her body replacing his), who might be either a witch or a vampire. I remember he was initially topless, so she somehow used his briefs to improvise a halter-top (she was busty and I remember it kind of stretched credulity for me), which led to his mother commenting the next day, I think "off-camera", asking how he'd stretched them out so much. He has no memories of the night, but I think she sucked out life energy from a guy she picked up in a bar.
We learn that, before the initial events of the comic, she was killed and buried by a group of men, then much younger. I don't remember if they killed her because they thought she was evil, or if it was something more malicious or accidental, but they've kept it a secret ever since. One of them is now a town official. One is a mortician (he's creepy and I think it's either implied or outright stated that he did something sexual to the girl either before or after her death). And the third is a long-haired priest, or minister, who's the uncle of the protagonist. Over the course of that first possession, I think she killed off another member of their group, so they meet to discuss what to do now that she's back.
Past that, I don't remember much, and I think that the comic stalled out... pretty sure that the girl confronted the priest at some point, and later on, she and the boy were able to talk to one another in their shared body. I think the title of either the comic or the site might have had something to do with an 8-ball... or maybe that was in their logo.
I remember the artwork as being in color at least some of the time, and it was non-realistic, but also not cartoony. People had normal proportions.
I have a vague memory of another comic (determined by frog42 to be Eight's Road Waffles, running on Keenspot from 1999-2004 along with two other comics, the site being named "Eightland") being related, maybe sharing a writer and/or artist, but all I remember about that comic was that one part had a ninja girl with a smiley-face mask car-surfing the protagonist's vehicle, and responding to them slamming the brakes by leaning impossibly far forward to avoid being thrown off, and a later arc where two boys pick up a female hitchhiker and, while they're at a gas station, one of the boys tries to force her to expose her breasts or they'll ditch her there (he might have used the Internet phrase of "Tits or GTFO"), leading to the other boy punching the first boy and apologizing to the girl. I'm not 100% that this comic is tied to it, but any small possible corroborating detail, right?