Elemental Killer

Air would probably be similar to nurse. Earth might be cool but I struggle to think how it'd be implemented. Fire feels like low hanging fruit and probably not as scary. I think they could make a pretty sweet drowned corpselike character with water powers that's spooky and unique.

Doctor is already an electric type Pokemon. Therefore, I guess that a pirate or drowned corpse killer would be nice for a another water type.

You know, since Sadako is already a Ghost/Water type.

I've said it before, but I'm a HUGE proponent for a Nautical Horror themed chapter. It's such an iconic sub-genre and yet we've seen so little of it represented in Dead by Daylight save for a few cosmetics like Trapper's Seaside Psycho.

There's a wealth of opportunity in Nautical horror, and as far as original concepts go I could definitely see a killer covered head to toe in a vintage diving suit wielding a harpoon. Other ideas I've thought of are an undead naval officer wielding an officer's sabre, an undead pirate or pirate captain wielding a cutlass, a creepy sailor with a whaling spear, or just your classic old sinister fisherman holding onto a long hooked fishing tool of some kind.

There's no shortage of map opportunities either, "The Lighthouse," "The Island," or "The Dockyard" / "The Docks" all sound like perfect harrowing locations that are all dark and mysteriously isolated or abandoned. Each covered in a thick, eerie, and unnatural fog. It could also be the first map with boundaries that aren't at all defined by walls, but instead by a vast ocean with choppy waves below menacingly looming storm clouds. The occasional sound of thunder accompanied by a bright flash of lightning really setting the tone for such a place.

Original concepts aside though, I have high hopes for a Licensed Bioshock chapter featuring The Big Daddy as a killer known in Dead by Daylight as "The Bouncer." With a giant drill strapped over one arm and access to various plasmids that grant supernatural abilities, there is so much room for The Big Daddy to flourish amongst the killer roster. Best case scenario this chapter would also be able to bring Rapture in as a map, and instead of trying to fit all of Rapture into one map you could easily make multiple maps of the different areas of underwater city. Worst case scenario there wouldn't be a map, but really The Big Daddy is the most iconic aspect of Bioshock that could be brought to life in DBD which would be incredibly cool.

Honorable mention though is a fire themed chapter. Someone else said this would be "low hanging fruit" but the fear of burning to death ranks pretty high amongst horrific ways to go, and I would personally love to see an original crazed fireman with a gas mask wielding a fireman's axe as a killer in DBD. The irony of emergency personnel condemning human lives instead of saving them is the perfect concept for the foundation of an interesting character story I think. Also we could finally see the "burned" status effect in Dead by Daylight, which you'd think we'd have seen a lot sooner in a hellish purgatory like place like the realm of the entity. You would think that burning to death would have come around in some form or fashion to Dead by Daylight a lot earlier than year 6 going onto year 7.