:( I couldn't post this on Dead by Daylight (Reddit) because the auto-moderator removed it... why is the world such a miserable, horrible, lonely, and hateful place? Kinda makes me want to... nvm
The Antichrist or the Devil -- the killer's name (your choice, my preference is the first one) and he has deadly powers of seduction with an array of darkly comedic pick up lines: specifically spoken words, and you need some good comedians to write these because they have to be likeable lines that appear charming and threatening at the same time. He seduces female and male survivors alike, except females have greater vulnerability than male survivors. The seductions can be done when he is within a certain survivor proximity and trigger skill checks for them.
After first hook, the survivor is "hooked", then he can use the "line" ability to make their heart beat and show their aura, then the "sinker" is when they seduction effect is at max and they kill themselves as a statement of devotion in front of a vision of him that appears (kinda like the Omen)
The vision appears to the survivor and their suicide downs them, but depending on his state (hold that thought) the notification the killer receives is based on a gradient from no notification to scream and aura reveal. This happens to males too, but there is a significantly unbalanced resistance/vulnerability between male and female survivors. However, female survivors can do a difficult skill check before being hooked to disarm him by seducing him, and be freed with a stun (up to two times). Men have no such ability.
If the seduced survivor is with another survivor who is not seduced when the vision appears at max seduction, the seduced survivor kills (downs) the non-seduced one with strangulation and ends the seduction. Or if they are all seduced they fight and have to pass skill checks to see who is downed with one left standing when the seduction ends. Takes time and makes noise, but still kinda quick. The thing is, it takes longer and with more noise the more survivors there are together, but that is turned against them. Additionally, when following blood trails or near blood, he exudes irresistible pheromones that induce states of oblivious euphoria for a short duration and speed up seduction.
Just use the same murder screams for the seduction ones. It's pretty much the same in real life anyway. He looks totally normal, like another survivor, except dressed like a priest and with a low terror radius to start. Now, remember that thought from before? Here's the thing-- the more he lands basic attacks and kills, the more he turns monstrous and his terror radius grows to give his presence away easier.
To counteract the powers of seduction, place vials of holy water throughout the map, which can be used to remove all effects of seduction and establish a brief duration of resistance
His basic weapon will be a brutal crucifix, and he'll lick the blood off of it after each hit.
The back story... you could really just reference my real life and do an interview with me to get the material, but I'll sum it up. It's basically like an opposite version of Michael Myer's story. He is a totally good seed, except born into the most evil and hateful environment possible, and has never known real love or acceptance that wasn't conditional in his entire life. Growing up, he makes it through a mostly normal life exceptionally well.
As an adult he has a modest career as a niche pulp novelist (not like Hitler, he is talented and has trained like you would expect a master violinist to, but it is not mainstream material which is why he doesn't become rich and famous for it). That was after service in the Navy (having a past as a sailor is significant). He has always abided peacefully for the most part and does not have a criminal record or significant trauma like you may expect-- his is like slow-building trauma over a very long time and nobody even noticed it until it was too late because they had been lying to themselves and him the entire time.
However... that all changes when all of a sudden he flips. Truth dawns on him about good and evil and he recognizes his family as evil and murders them all. Then, he is acquitted from all charges of murder when he explains himself in court. After that, he can't find satisfaction in life anymore and wanders aimlessly as a drifter for some time.
Everything appears evil to him. He lives by an incredibly strong sense of faith and piety but it is of no avail for him because he ultimately succumbs to the darkness that has always engulfed him for having been born into such hateful family circumstances. It is his last straw and cannot resist making it his sole purpose in life to kill every last human being on the planet. When he finally has the resolve to become a true serial killer, it is like madness totally taking over his mind after a long, hopeless struggle against it, and that is when the Void opens and takes him away.
That will be 1 billion dollars. You're welcome. jk, just make it happen. Pay me what you think is fair.