Isekai heroes don’t seem to have a middle ground. They’re either super overpowered being able to use any type of magic or have a magic item that makes them much stronger than normal. Very rarely are the heroes not too strong or not too weak.
Many of the best isekai protagonists take the extremes at both ends, with some being scrappy and resourceful underdogs and others being juggernauts who have the strength and spells to win any fight, easy-peasy. Both routes are valid, with the former follow traditional storytelling routes and the latter being sheer escapism, but both can make for a fine isekai adventure.
Update June 2nd, 2021 by Louis Kemner: The anime world is highly saturated with isekai titles by now, but the genre is still going strong, and many light novel authors and manga artists are finding new design space within the genre to make their titles unique. Who are some other recent isekai heroes who should be discussed?
15 Weakest: Louise Francoise Le Blanc de la Valliere (The Familiar of Zero)
Louise Francoise Le Blanc de la Valliere is a mage that is unable to use magic. Because of this she gets the nickname Louise the Zero. On top of not being able to use magic, Louise is self-centered and refuses to admit she is falling in love with Saito.
The Familiar of Zero follows Saito and Louise while they study at Tristain Academy, and these two would make it onto any list of couples who shouldn’t be together. The Familiar of Zero was released during the summer 2006 season and aired for 13 episodes.
14 Strongest: Naofumi Iwatani (The Rising Of The Shield Hero)
You might think Naofumi Iwatani is weak because he only wields a shield, but he is anything but that. Naofumi has a hot temper but controls it well behind a cool and rational demeanor. The Legendary Shield he has once belonged to a group of four heroes who wielded a sword, spear, and bow respectively.
After being betrayed by Princess Malty, Naofumi becomes a hated man trying to survive. The Rising of the Shield Hero was released during the winter 2019 season and aired for 25 episodes.
13 Weakest: The Goblin Slayer (Goblin Slayer)
Goblin Slayer is a unique character where he’s tactile and smart in battle, but only on one condition. He is only strong against goblins. He knows the ins and outs to fighting goblins having fought them exclusively his entire life.
While he can easily slay many goblins even if outnumbered severely, he has no experience fighting anything else. Good thing the series isn’t Zombie Slayer. Goblin Slayer was released during the fall 2018 season and aired for 12 episodes.
12 Strongest: [Blank] Is An Invincible Duo (No Game No Life)
Blank is made up of two characters: Shiro and Sora. Shiro is the superior of the two, but Sora is no push over. Blank is the screen name they use. Both siblings are hikikomori NEET’s that are exceptional at playing games.
When the two siblings are together, they compliment each others’ strengths, unable to be defeated by anything in the world of Disboard. The series follows their adventures in Disboard as they try to unite the 16 races in the series. No Game No Life was released during the spring 2014 season and aired for 12 episodes.
11 Weakest: Kazuma Sato Is A Sleazy But Lucky Adventurer (Konosuba: God’s Blessing On This Wonderful World!)
Kazuma Saito may be an isekai protagonist in a fantasy realm, but he's hardly a powerhouse. Instead, he is a low-class adventurer with very few abilities aside from his formidable Luck stat. He can use basic magic, detect monsters, and has a signature ability called “Steal”.
While in theory, this ability could be useful, Kazuma is often just using it to steal the panties off the other characters. Konosuba was released during the winter 2016 season and aired for 12 episodes.
10 Strongest: Izayoi Sakamaki His Immense Psychic Abilities (Problem Children are Coming From Another World, Aren’t They?)
Izayoi Sakamaki has exceptionally strong psychic powers. Being stronger than everyone else, he is summoned by the Black Rabbit to Little Garden to help a community known as “No Names” who were destroyed by the demon lord.
Problem Children are Coming From Another World, Aren’t They? was released during the winter 2013 season and aired for 10 episodes.
9 Weakest: Sadao Mao Now Flips Burgers (The Devil Is A Part-Timer!)
The Demon King of his original world, Sadao Maou was sent to the human world and became a human. In the human world Sadao lost all his powers and finds a job working fast food at MgRonalds. Sadao is ultimately powerless as he is just like everyone else.
The human version of Sadao now has to face his biggest challenge yet, paying rent. The anime follows him as he works his way up the corporate ladder trying to find a way back to his world. The Devil is a Part-Timer was released during the spring 2013 season and aired for 13 episodes.
8 Strongest: Rimuru Tempest Is An International Politician & Fantasy Fighter (That Time I Got Reincarnated As A Slime)
Rimuru Tempest, formally known as Satoru Mikami, is a slime that founded the city known as Tempest. When Satoru was reincarnated as a slime, he gained many difference abilities such as mimicry, nullification, and magic.
He was given the name Rimuru Tempest by Veldora the Storm Dragon in return for breaking his seal. That Time I Got Reincarnated as a Slime was released during the fall 2018 season and aired for 24 episodes. Now the second season is well underway, and its second half will begin airing July 2021.
7 Weakest: Masato Oosuki Is Overshadowed By His Mom (Okaasan Online: Do You Like Your Mom? Her Normal Attack Is Two Attacks At Full Power)
Masato Oosuki wanted to be the main character trapped in a video game with the power to fight his way out. However, all the power went to his mother that also got trapped in the game too. Together the two form a party to fight monsters they meet along the way.
The catch is, Masato’s mother Mamako is overpowered being able to kill anything in a few hits. This often leaves Masato demoralized as he doesn’t get to fight much in the series. Okaasan Online inspired many memes and was released during the summer 2019 season and aired for 12 episodes.
6 Strongest: Shin Walford Is Awkward But Mighty (Wise Man’s Grandchild)
Arguably one of the strongest isekai characters out there, Shin Walford can use an unprecedented amount of magic and is skilled in martial arts. There isn’t anything Shin can’t do…except use common sense. Shin may be strong, but he is also awkward.
He attends the Magic Academy where he wows everyone with his skill, but has some interesting interactions talking to Sicily von Claude, the girl who has a crush on him. Wise Man’s Grandchild was released during the spring 2019 season and aired for 12 episodes.
5 Weakest: Yuzuhira Ogawa Is A Tailor & Artisan, Not A Fighter (Dr. Stone)
Yuzuriha Ogawa is an example of a character who is weak, but not useless by any means. She is one of several high schoolers to emerge in the new stone age 3,700 years in the future, making her, Senku and Taiju time-based rather than portal-based isekai heroes.
Around here, Senku is the #1 scientist and engineer while Taiju is a manual laborer, leaving Yuzuriha as a tailor and an expert in piecing together broken, petrified people. Yuzuriha can't fight, she must be protected at all times. Fortunately, she has more than a few friends to keep her safe.
4 Strongest: Azusa Aizawa Reached Level 99 & Can Demolish Any Foe (I've Been Killing Slimes For 300 Years And Maxed Out My Level)
This short, ongoing isekai series turns the genre on its head a little by giving its heroine immense power, but very little will to use it. Azusa Aizawa worked herself to death in real-life Japan, and now, as an isekai heroine, she has one mission: Take life easy. Forever.
Instead of going on incredible quests, Azusa patiently hunted slimes to slowly grind XP and gold, and after three centuries, she hit level 99 and became a true powerhouse. She can beat anyone, even the demon king, but Azusa would rather spend her time making friends and helping them with their problems.
3 Weakest: Natsuki Subaru Is Stubborn & Immortal But Not Powerful (Re:ZERO)
Natsuki Subaru might be the most famous isekai hero right now, known for his orange and black tracksuit and his constant deaths. Subaru was not born as an almighty slime or witch; he is just a kid with the ability to come back to life at the last checkpoint, and this lifestyle is highly taxing.
Subaru has just one advantage: his ability to restart at a checkpoint and know what will happen, and when and how. His adventure is a long, painful session of trial and error, and in a fight, he can't do much. Good thing Emilia and Rem are on his side.
2 Strongest: Kirito Is A Sword-Slinging Hero (Sword Art Online)
Kirito, the lone swordsman, is another well-known isekai protagonist. His isekai adventure is the video game variety, in which he and thousands of other games got trapped in the virtual world of Aincrad and had to fight their way out. Dying in the game means dying for real.
Kirito persisted despite the odds, and he even used two swords at once, an incredibly rare skill. He wielded powerful blades such as Eludicator and Dark Repulser in battle, and later in other games, he wielded swords such as Excalibur and a lightsaber-ish sword called Kagemitsu G4.
1 Weakest: Aoi Tsubaki Is A Chef, Not A Warrior (Kakuriyo: Bed & Breakfast For Spirits)
Aoi Tsubaki is an isekai heroine who proves that there's much more to isekai than power fantasies or harems. Like Senku Ishigami and Myne, Aoi is a constructive and peace-oriented isekai protagonist, and she is known for her cooking skills in particular.
Aoi find herself in the world of ayakashi (monsters) before long, and she is asked to prepare all kinds of wonderful dishes for her supernatural patrons. She can't do much in a fight, so it's up to Odanna to protect her.