Isekai as a genre perhaps started with stories that were a bit more straightforward and even fantastical with the likes of The 12 Kingdoms and even Inuyasha taking center stage. Modern isekai is a little different because there are more comedic elements that go along with the plot.
Therefore, one would normally never pair isekai and horror as a reasonable match. Now, while there is currently no horror show that you could say is an isekai, there are a handful of isekai shows that have horror elements. This could be their setting, design or how the story goes.
5 Funeral service
Gore, Gore and Gore
To be honest, Corpse Party is a horror anime with very little isekai in it. It started life as a video game that came out in 2008 and gained a devoted following. A single episode OVA followed in 2012 called Corpse Party: Missing Footage and was then followed by Corpse Party: Tortured Souls in 2013 which simply picked up where the first OVA left off. Some students end up trapped in an alternate dimension that might count as another world in some way. But that's about as much isekai as a person will find in this show.
But on the horror front, Corpse Party delivers the horror and misery. Now for some Corpse Party is lacking in the story department and with only five episodes in total it is almost impossible to know or really root for any of the characters, but then the people who want to see individuals killed in the most grotesque ways will not be disappointed .
4 Grimgar of Fantasy And Ash
A depressing look at the reality of Isekai
What is horror? It is a feeling that makes a person care, to feel some kind of fear or dread. So while Grimgar of Fantasy And Ash might not be the first name that comes to mind when considering isekai horror, it is firmly placed within that genre. It is a story that looks at the reality of isekai. Instead of an exciting adventure where everyone gets cool powers, it can be a terrifying experience about fighting to survive.
Family
7 Saddest Isekai Anime & Manga
In addition to taking viewers to new worlds, these series convey a deeper storytelling style that can bring tears to your eyes.
The horror of Grimgar is how relatable it is. If some average Joe is actually sucked into another world where they have to fend for themselves, fight monsters they've only read about in books, and struggle to find companions as they make their way through the world, it can be pretty scary indeed.
3 Error frame
The visuals can act as nightmare fuel
Failure Frame is an isekai anime still running for the Summer 2024 anime series. It follows Touka Mimori, a loner who ends up being transported to another world along with all of his classmates. He finds that he has the least attractive ability, everyone discards him and he is sent to his death, but somehow the power turns out to be OP and he is strong enough to clear all content in his path.
Failure Frame is a generic show, with some animation that viewers found less than impressive. But it also comes with some gruesome visuals that give it the required horror elements. The world is depressing and some of the monsters evoke fear. In Episode 2, the protagonist encounters a monster known as the Soul Eater while winning the fight, many will walk away from that fight with the grotesque design of the monster stuck in their head.
2 Re: Zero – Starting Life in Another World
Subaru's Sad Loop is terrifying to think about
When Re:Zero -Starting Life in Another World was first released in 2016, it was praised for doing certain things that other isekai at the time just didn't have. It followed Natsuki Subaru, an ordinary boy who is then taken to a fantasy world. Finding his way to help a young lady, he is killed, but then finds himself alive again in a familiar situation before the events that led to his death occurred.
Re:Zero featured several elements that set it apart from other shows at the time, including a less-than-ideal protagonist who wasn't OP by any means, but finds himself in a world he doesn't understand. The horror elements show in how Subaru dies. He knows every death which makes it quite scary. Also, with Subaru mostly powerless, going up against certain entities that are so much more powerful than him brings its own sense of dread.
1 Overlord
Terror for all allies against Ainz
Overlord is a very popular isekai that has been adapted from a light novel. The world of YGGDRASIL is very interesting with different factions and kingdoms looking out for their own interest while Ainz is also in it for the good of his race.
Quite fascinating is the fact that many of Overlord's horror elements come from the protagonist and his faction. When all is said and done, Ainz is the master of some very nauseating subjects, who have hair-raising desires. When watching scenes where Ainz dispatches people he considers enemies, it can be hard to see. Examples include Ainz's annihilation of an entire army with some pretty scary monsters, the torture of the workers who met the most horrific fate, Clementine's death in Season 1… all of this shows that Overlord is not a show for the faint of heart.
