While some isekai protagonists get transported to new, fun worlds, the grass isn't always greener. Some isekai worlds are dark, brutal, and unforgiving, making the main character wish they could go back home. Dark isekai is a newer addition to the wider genre of isekai, and it doesn't have too many entrants. Most isekai series focus on the brighter side of life and give their characters fun powers in their vibrant new worlds. Dark isekai do the opposite, usually leaving the main character in a harder environment than they can initially handle.

Some characters, like Ainz from Overlord, are perfectly capable of handling the environment they're in and instead choose to be the world's villain. It's not entirely a dark world for Ainz, but it sure is for everyone who isn't his friend. Dark isekai have a unique opportunity of pitting the main character against the world their isekai'd into, not the opposite.

10 Dr. Stone

Animated By TMS Entertainment, Based On The Manga By Riichiro Inagaki & Boichi

Dr. Stone starts out dark. Senku Ishigami is a super-intelligent high-school student who, along with the rest of the world, gets petrified in a hue of green light. He wakes up well over 3,000 years later to a completely new world devoid of all the people he once knew. He meets a few people along the way to keep him company, but they're few and far between. He spends the series looking for a way to revive everyone, and even though that's a noble goal, there are already people he can't bring back.

Some people who were petrified have been broken during the thousands of years since they were awake. Some were broken by accident, and others were broken on purpose. It's a dark reality Senku has to live with in this Stone World as he looks to navigate new relationships and the environment around him.

9 No Game No Life

Animated By Madhouse, Based On The Light Novel By Yuu Kamiya

No Game No Life is a pretty irreverent show, but it can also be pretty dark. Before Sora and Shiro, two of the smartest isekai protagonists around, came to the world of Disboard, Humanity was in a terrible position. They were ranked last out of all the races and really had no chance of improving their position. They didn't have any land and had no prospect of beating the races that put them in the position they were in. Luckily, Sora and Shiro were able to win a few important games to win back some of the pride and land that the race had lost.

Sora and Shiro were lucky when they found the world of Disboard. In their past lives, they were the best gamers in the world by some margin. They were so good, they got bored. Coming to their new world has given them their spark again. They're happy playing games, and even happier that they can use all of humanity as a betting piece as well.

8 The Ascendance of a Bookworm

Animated By Ajia-do Animation Works & Wit Studio, Based On The Light Novel Series By Miya Kazuki

Main is one of the most humble characters in isekai. While Rimuru from That Time I Was Reincarnated as a Slime wants to change the world, and Ainz from Overlord wants to dominate it, Main just wants to read. She has the worst luck of the trio, as she was reincarnated into a world where books were very hard to get. Not only was she born into a world without her favorite thing, but she has a terrible disease as well.

The Devouring is slowly killing Main. Without expensive magical items, it'll kill her soon. It's a dark premise that doesn't get much lighter throughout the show. Main, however, almost never has a bad attitude about her situation. There have been a couple of times when she's faced some low moments, but for the most part, she's an optimistic character that will make her own books if she has to.

7 I Was Reincarnated as the 7th Prince

Animated By Tsumugi Akita Animation Lab, Based On The Light Novel By Kenkyo na Circle

I Was Reincarnated as the 7th Prince So I Can Take My Time Perfecting My Magical Ability is a much darker isekai series past the surface. At first glance, it's a lighthearted show about a man who was able to perfect his magical craft once he was reincarnated into the royal family. It's not all fun and games for the people in 7th Prince, as some of the villains in the series put other characters through absolute misery. Jade was the enigmatic leader of the Assassin's Guild before he was possessed.

His possession drove him insane, leading him to kill himself several times before his spirit was finally broken. Guisarme, the Demon who took over Jade's body, even recounts Jade's death to his friends. He manipulates and tortures Jade, detailing the events to his former allies. It's a pretty dark turn of events for what otherwise can be a funny and jovial show. I Was Reincarnated As The 7th Prince may share some DNA with Dragon Ball, but that doesn't mean it doesn't have its own bits of darkness.

6 Mushoku Tensei: Jobless Reincarnation

Animated By Studio Bind, Based On The Light Novel Series By Rifujin na Magonote

Mushoku Tensei: Jobless Reincarnation is both one of the most controversial and most compelling anime in the last decade. It stars Rudeus Greyrat as he navigates his second life with incredible powers, great friends, and plenty of love interests. While the series has plenty of remarkable highs, its no stranger to devastating lows. Mushoku Tensei is better than most anime at making the viewer feel confident about a situation only to pull the rug out from under them.

One of the darkest moments in Mushoku Tensei was during the second season when they aired Rudy's dad Paul's death on Father's Day. It was a sad death that aired on an ironic day. Rudeus constantly faces tough odds on a divine level. He works as hard as he can to overcome them, and with the people ing him, he should be able to.

5 Drifters

Animated By Hoods Drifters Studio, Based On The Manga By Kouta Hirano

Drifters is a unique isekai that sees history blend together with fantasy in a new, dark setting. Toyohisa Shimazu was protecting the rear guard during a battle in Japan in the 1600s when he was nearly killed. Before he dies, he's pulled into a new world by a mysterious figure. He enters the world of Drifters, who need his help fighting against the Ends, an entirely new type of enemy. It's an intriguing story that makes for a great, quick watch.

Toyohisu leaves one battlefield to enter another. It's a dark turn of events for him that never gets much better. He's not alone in his struggles though, as he's able to find powerful allies who were pulled into this world similarly. His fellow Drifters Oda Nobunaga and Nasu Yoichi are there alongside him in his grueling fight against the Ends.

4 Grimgar Ashes and Illusions

Animated By A-1 Pictures, Based On The Light Novel Series By Ao Jūmonji & Eiri Shira

Not many series start as bleak as Grimgar Ashes and Illusions. Haruhiro, Manato, and more had suddenly woken up in a new location without any prior knowledge as to who they were. They were asked if they wanted to a Volunteer Force and didn't really have a reason or way to say no. The series only gets darker from there with the death of several key early in the series. Grimgar got a lot of attention early for its eye-catching watercolor art style and willingness to dive into such bleak territory.

Haruhiro has too much thrust onto his plate. He wants to be the best leader he can for the rest of his troops, but it's incredibly demanding. His friends are dying in front of him way too often for him to retain his cool, but somehow he does. It's a dark isekai series from the moment Haruhiro wakes up, and it doesn't get much better going forward.

3 The Saga of Tanya the Evil

Animated By NUT, Based On The Light Novel By Carlo Zen & Shinobu Shinotsuki

The Saga of Tanya the Evil sees a normal Japanese salaryman reincarnated in a new world as a small girl named Tanya. When the salaryman died, he met Being X and told him he didn't believe in metaphysical entities like Gods and Demons. Being X was intrigued by the salaryman's indignation, so he sent him to learn about life in a new world. Tanya's new world is brutal. It's a world at war, and she's at the front of it all.

While Tanya is a walking one-man-army on every battlefield she's on, it doesn't make her job easier. She has to kill battalions of enemies to defend her country, and even then the fight isn't looking good. She was able to take some time to retire from the front lines, but her war isn't won yet.

2 Overlord

Animated By Madhouse, Based On The Light Novel By Kugane Maruyama & so-bin

Overlord is an isekai series that sees Ainz Ooal Gown trapped in a video game. While most other characters might try to learn more about the world around them, Ainz looks to dominate it. He wants to become the Supreme Ruler of the entire world in an attempt to find another real-life player like himself. Unfortunately for the denizens of Yggdrasil, Ainz is willing to commit tragic events of mass destruction in order to make it happen.

Overlord is a pretty dark isekai series for a couple of reasons. Ainz really is alone in his position as the only real person left in Yggdrasil, at least until he finds someone else. It's even darker for anyone who isn't involved with the Great Tomb of Nazarick as Ainz looks to be an absolute Overlord. He crushes anyone who stands in his way and is capable of erasing entire armies with a single spell.

1 Re: Zero - Starting Life in Another World

Animated By White Fox, Based On The Light Novel Series By Tappei Nagatsuki

Re: Zero - Starting Life in Another World can feel almost too bleak at times. The show stars Natsuki Subaru as he's isekai to a new world and granted one of the most bittersweet powers in anime in Return by Death. His new ability gives him the power to return to a predetermined point in time after he's died. While it's helpful for him to accomplish his goals, Subaru has to suffer a series of increasingly brutal deaths because of it. He's already died more than a dozen times in the anime, and it doesn't look like it's getting better any time soon.

Re: Zero is the darkest isekai anime because of how hopeless it can feel. Subaru can figure out a way to live in one instance, only to die in another, restarting at point zero. While there is a cheery cast of characters ing him, the theme of Re: Zero couldn't be much darker.