BL for horror lovers
Manga
Not recommended for those who are easily disturbed - contains adult content such as violence, physical/psychological torture and sensitive topics. Those without comments are manga/manhwas that I haven't read yet, or that I finished a long time ago and want to read again before commenting.

Manga, ? vol, 2021
Me:-
Author:10
There's not much to say about this one, for me it's perfect in every aspect and my only complaint is having to wait a month or so to read a new chapter. One of the best examples of how to make a manga for both horror and BL fans. The best manga you'll find on this list.
*Ongoing
*Shounen-ai/not explicit
*Supernatural
*Ongoing
*Shounen-ai/not explicit
*Supernatural

Manga, 1 vol, 2021
Me:-
Author:10
Beautiful art, great story, no fanservice and extremely engaging. It has only one volume, five chapters and one special, which means it can be finished in about 2 hours or less. I highly recommend it and can confidently say it's a masterpiece.
*Psychological
*Psychological

Manga, 10 vol, 2013
Me:-
Author:10
It took me a long time to finish this piece of work, not because I was procrastinating, but rather because I didn't want to finish it; I got attached to the characters - that's one of the main points of this manga, character development plus easily likable characters, as well as a good story that develops without being too slow or rushed.
I don't know exactly how to classify the BL part, as "not explicit" would be rather ironic considering certain scenes that were clearly meant to be erotic and extremely suggestive (as well as comedic). The relationship between the protagonists is very well developed, making it clear at a certain point that there are romantic feelings involved (even though not explicit you'd have to be a little stupid not to notice it). In general, a shounen-ai for those who have always dreamed of reading a seinen or shounen manga with a good story, plot and not focused on romance, but BL.
*Shounen-ai... but explicitly? Idk
*Supernatural
I don't know exactly how to classify the BL part, as "not explicit" would be rather ironic considering certain scenes that were clearly meant to be erotic and extremely suggestive (as well as comedic). The relationship between the protagonists is very well developed, making it clear at a certain point that there are romantic feelings involved (even though not explicit you'd have to be a little stupid not to notice it). In general, a shounen-ai for those who have always dreamed of reading a seinen or shounen manga with a good story, plot and not focused on romance, but BL.
*Shounen-ai... but explicitly? Idk
*Supernatural

Manga, 4 vol, 2001
Me:-
Author:9
This is the typical manga for those who have found themselves thinking "Man... I want to read something in the style of [insert old, famous shounen/seinen manga here], but BL." The story is well-written and well-developed, as are the characters. The BL part takes the back seat for most of the manga, which really focuses on the plot, while the "horror" is mixed with comedy, action and mystery (as well as some pretty dark/depressing stuff such as bullying and suicide). Highly recommended! 29 chapters, 4 volumes.
*Shounen-ai/not explicit
*Supernatural, action
*Shounen-ai/not explicit
*Supernatural, action

Manga, ? vol, 2024
Me:-
Author:-
Like two of the mangas above (Otsukaresama, Kurose-kun and Kimi no Yoru ni Fureru), this one is also serialized by RED, and although only in its first chapters - which will apparently be released every two months - has already become one of my favorite ongoing mangas. A promising story involving ghost haunting, complicated relationships and dark comedy.
*Ongoing
*Supernatural
*Ongoing
*Supernatural

Manga, ? vol, 2024
Me:-
Author:-
Finally... The long-awaited manga is out! I have high expectations for this masterpiece, and the first chapter was all it took to prove that it has great potential. How can I explain? It's a mix of Mieruko-chan and Hikaru ga Shinda Natsu. The art is beautiful, the story is promising and apparently the chapters will also be released every two months. A great new manga to follow!
*Ongoing
*Supernatural
*Ongoing
*Supernatural

Manga, ? vol, 2021
Me:-
Author:-
A comedy manga about a vampire obsessed with keeping a 15-year-old boy's virginity intact... Yep. I don't know if this manga fits the term "BL" because there's no romance between the protagonists - at least not as far as I've read - but anyway, I'm sure you'll enjoy it if you like gay vampires obsessed with drinking the blood of young virgins. Also, the artwork is beautiful and the story is very well written. I highly recommend it.
*Ongoing
*Vampires
*Ongoing
*Vampires

Manga, ? vol, 2022
Me:-
Author:-
One of my favorite ongoing manga, the art is extremely beautiful and the story certainly has a lot to offer. The "horror" part of this manga is the supernatural kind, and the main focus is on the action, but I think it's still fair to mention this work of art. Highly recommended!
*Ongoing
*Shounen-ai/not explicit - yet, at least
*Supernatural, action
*Ongoing
*Shounen-ai/not explicit - yet, at least
*Supernatural, action

Manga, ? vol, 2022
Me:-
Author:-
I honestly didn't have many expectations when I started reading this manga, but I was surprised by how good it is. A murderer is obsessed with an average employee who lives a monotonous and miserable life. This murderer happens to be his former classmate, while the employee happens to be the only one who showed him the slightest bit of compassion back in school. Highly recommended!
*Ongoing
*Serial killers, adult content, violence
*Ongoing
*Serial killers, adult content, violence

One-shot, ? vol, 2021
Me:-
Author:9
A 12-page one-shot by Mokomoku Ren, Hikaru ga Shinda Natsu's author. Apart from the art which, as you'd expect from the author, is stunningly beautiful, the manga although extremely short is enough to get a good reaction out of the reader, at the same time as sufficient for you to understand what led the characters to do what they did as well as their reasons for doing it - well... sort of. Good for those who like a quick read full of violence and an unhealthy relationship.
*Psychological, violence
*Psychological, violence

Doujinshi, 1 vol, 2017
Me:-
Author:9
Extremely short (oneshot), but with a lot to offer. I don't understand why the rating for this manga is so low, but don't let that stop you from reading it. A great recommendation for those who like zombie-themed manga and a somewhat messed up relationship.
*Post-apocalyptic, zombies
*Post-apocalyptic, zombies

Manga, 1 vol, 2014
Me:-
Author:9
The first time I read this manga years ago, I didn't like it, and now that I've read it again, I can't understand why. It's a manga that doesn't need to use and abuse gore, violence or appealing things to express its dark theme about a priest, a thief and a cult; it has a good story and characters that are very well developed throughout the chapters, which is difficult in a BL, let's be honest. Highly recommended! 4 chapters, 1 volume.
*Psychological, adult content
*Psychological, adult content

Manga, 1 vol, 2015
Me:-
Author:8
I was really surprised by the quality of this manga in general, from the original and engaging story (even though I found the plot a bit predictable), characters who are still extremely likeable even with little development, and most of all the artwork - which is beautiful. I'd say it's a great recommendation if you're looking for a BL with horror elements and a bit of mystery, plus a historical setting. 6 chapters, 1 volume.
*Supernatural, historical, serial killers
*Supernatural, historical, serial killers

Manga, 2 vol, 2020
Me:-
Author:8
Okay... This one is only for the strong souls who aren't afraid of getting a little traumatized. An extremely dark manga dealing with trauma and bullying, with a mad scientist, a living dead man, and lots of cannibalism. For those of you wondering, "Is it really a BL or does it just have a homoerotic subtext?" the answer is... yes, it is a BL with an excellent development of the protagonists' relationship. 12 chapters + 1 special, 2 volumes.
*Supernatural, zombies, psychological, gore, adult content
*Supernatural, zombies, psychological, gore, adult content

Manga, 1 vol, 2019
Me:-
Author:8
Another one recommended only for the strongest soldiers who have read a lot of traumatic stuff and no longer fear anything. It's a manga full of themes that might trigger some people, so if you're not very fond of taboo, disgusting and sickening stuff, steer clear of it. 6 chapters, 1 volume.
*Supernatural, zombies, gore, adult content
*Supernatural, zombies, gore, adult content

Manhwa, 2 vol, 2008
Me:-
Author:8
It's not really horror, but I thought it would be good to give it an honorable mention since the relationship between the protagonists is pretty messed up. I've seen some people complain about the art, but don't let that stop you from reading this manhwa about a suicidal 18-year-old and a 25-year-old fugitive and murder suspect. 12 chapters, 2 volumes.
*Shounen-ai/not explicit
*Psychological
*Shounen-ai/not explicit
*Psychological

Manhwa, 3 vol, 2018
Me:-
Author:10
An honorable mention, if you like webtoons and K-dramas as much as I do, you may already know this masterpiece. It's not a BL, but it's basically a Korean version of Hannibal... in a way. Mr. Room 203 guy is pretty much obsessed with the protagonist, and he makes it very, very clear. In the K-drama adaptation fandom, they're known for the number of edits involving them.
*THIS WEBTOON IS NOT A BL, but you'll certainly enjoy it if you like BL and are into horror
*Psychological, serial killers, extreme violence
*THIS WEBTOON IS NOT A BL, but you'll certainly enjoy it if you like BL and are into horror
*Psychological, serial killers, extreme violence

Manhwa, 5 vol, 2016
Me:-
Author:7
If you read the manhwa above, you'll want to read this one. Another cliché with captivity, Stockholm Syndrome, an unhealthy relationship, a predictable plot, and a lot of abuse. 72 chapters, 5 volumes.
*Psychological, adult content, violence
*Psychological, adult content, violence

Manga, 1 vol, 2020
Me:-
Author:6
I honestly don't know what to think about this manga, it's very peculiar and a lot of things are left to the reader to draw their own conclusions - in other words, not explicit, but a sub-context. By the way, the main characters are brothers, so.. yeah. 6 chapters, 1 volume.
*Shounen-ai/not explicit
*Psychological, violence
*Shounen-ai/not explicit
*Psychological, violence

One-shot, ? vol, 2016
Me:-
Author:2
I'll just leave this here in case you're a masochist and want to torture yourself by reading this shitty 33-page one-shot. I don't recommend it.
*"Psychological," adult content
*"Psychological," adult content

Manga, 2 vol, 2015
Me:-
Author:-
I've never read this manga, but based on the synopsis and the fact that it was written by Harada, I think we already have an answer as to why it's here. Sounds like a great choice if you like psychological horror, erotica and maybe a bit of trauma. 13 chapters, 2 volumes.
*Psychological, adult content (probably)
*Psychological, adult content (probably)