Of all the anime genres out there, the isekai sub-genre is likely the most oversaturated at the moment. There are so many stories of people being reincarnated into fantasy worlds, getting transported to be a hero in some medieval land or some other variation of this same base concept.
Because there are so many out there, many of the beloved older isekai or the adventurous new ones try to separate themselves from the pack in any way they can, with a common example being the story featuring a protagonist with some odd superpower. So, let's go over some of the premier examples of isekai MCs with powers that are on the more "unique" side.
8 Ginta Toramizu: MAR - Marchen Awakens Romance
MAR: Marchen Awakens Romance is an older isekai from 2003 that isn't one of the more renowned or extra-popular stories. In it, a young boy gets transported to a fantastical world filled with all kinds of magic items called "ARMs" that people use in all sorts of ways. And, while there's a lot that makes Ginta unique compared to everyone else in the story, his most unique power has to be Babbo, the living ARM that looks like a giant Kendama AKA a ball-and-cup toy.
Babbo is a unique ARM in that he has a "soul" and can turn into ARMs of any type be they other weapons, guardian ARMs, healing ARMs, and many more. But in his base form, Ginta literally swings around a Babbo, a sentient metal ball on a string, as a weapon, and that's pretty odd. Or, at least, it was until Reincarnated as a Sword came out.
7 Touya Mochizuki: In Another World With My Smart Phone
Funnily enough, Toya Mochizuki, the protagonist of In Another World With My Smart Phone is almost a textbook example of the standard "overpowered" isekai lead. His new isekai body is made of god-realm materials, he's able to use all types of magic, he has enhanced strength and durability, and he can even use divine powers that only gods would normally be able to use.
All that said, none of these powers are what the anime is named after, that's left to Touya's smartphone which the "God" of his world allowed him to keep. And, the ability to have an internet connection, GPS, or any of the other vast array of tools a modern smartphone provides in a medieval-esque world is absolutely a type of superpower and one that's pretty uncommon.
6 Hajime Nagumo: From Commonplace To World's Strongest
Next up is another hilariously overpowered protagonist, Hajime Nagumo. But, unlike other isekai MCs that are "born" with their cheat abilities, Nagumo actually got the short end of the stick and only started ramping up to god-like power levels due to toughing it out at the bottom of Orcus Labyrinth and eating monsters.
Still, at a basic level, Hajime has the "Job" called Synergist, which is typically a job used by blacksmiths and craftsmen as it allows him to modify materials around him with high levels of precision on a small scale. But, by stacking a lot of extra benefits on top and using his otherworldly knowledge, Hajime uses this Job to create magical guns, turning him from a pseudo-blacksmith into an edgy hotshot gunsmith.
5 Rein Shroud: Beast Tamer
Beast Tamers aren't anything new in any form of media. There are beast-tamer classes in video games, all sorts of fantasy stories, and even in settings like Dungeon and Dragons. That said, Rein Shroud's version of Beast Tamer is pretty unique.
For one, he can enter into contracts with the demi-human races of his fantasy world, which has its own share of questionable ethics. But, even more than this is the fact that when Rein does make a contract with a higher race such as a Dragon or a Dryad, he gains their innate racial traits himself. When compared to other Beast Tamers in his world, Rein is something special, and if he wasn't such an absolute sweetheart, the guy would be absolutely terrifying.
4 Sudou Kaname: Darwin's Game
Darwin's Game is a rare example of an isekai-esque setting where, instead of being transferred or reincarnated in another world, the world they live in just suddenly reveals this supernatural side to it. The main character of this series, Sudou Kaname, has a unique power too. Though, to be fair, everyone who installs Darwin's Game gets a unique "Sigil" when they start, though Sudou's is one of the weirder ones.
His power is called Hinokagutsuchi, and it essentially allows him to create "copies" of objects he touches, such as touching a pen and making another one in his hand. Now, at a glance, that seems pretty weak, but Sudou can make copies of any object he's ever touched, which instantly makes the ability a whole lot more useful. The weirdest part, however, is that Sudou doesn't immediately understand his Sigil when it's given to him, which is something that no other Darwin's Game player can relate to.
3 Kazuya Souma: How A Realist Hero Rebuilt The Kingdom
How a Realist Hero Rebuilt the Kingdom is another unique isekai simply because it has a different goal than most other stories in the subgenre. Instead of following a hero adventuring around some fantasy world using their cheat abilities, this anime follows one high school kid who is suddenly transferred to a new world and saddled with the responsibility of being king of a kingdom, Elfrieden, a land rife with problems.
To be fair, this story does have a lot of the standard isekai tropes like the main character having a harem, there being demi-human races, and there even being a magic system in place. But, unlike other stories, characters in HaRHRtK can usually only use one "type" of magic. For Souma, it's darkness, and he uses this magic in an incredibly odd way. The ability is called "Living Poltergeist" and it allows Souma to imbue objects with either a part of his consciousness or all of it. Most notably, Souma uses this to control his self-made puppet, Master Mascot, and go on adventurer quests to gather intel.
2 Makoto Misumi: Tsukimichi - Moonlit Fantasy
The list of abilities that Makoto Misumi has after being transferred to a new world in Tsukimichi: Moonlit Fantasy is staggering. The guy is essentially a god even in the first few episodes of the story. And, even though Makoto himself thinks he "sucks" at magic, that absolutely isn't the case. As proof of this, he makes an ancient dragon and a demon spider his underlings without really even trying. But, among all his absurd powers, the one that Makoto uses the most was actually given to him by the "god" of his previous world, Tsukuyomi.
It's called "Realm" and it essentially allows Makoto to create a dome around him that he can then apply properties to such as strengthening, healing, observation, and so on. Within this realm, these properties are absolute, and they basically allow Makoto to freely modify the world around him.
1 Yuna: Kuma Kuma Kuma Bear
Lastly, let's talk about probably the most ridiculous character and power on here, the power of Yuna's Kuma costume in Kuma Kuma Kuma Bear. Now, this anime is much like other "transported to a video game world" isekai stories such as some of the all-time greats like Sword Art Online or Log Horizon, but, instead of transferring into the body of their character, Yuna is instead transferred into her own body and is instead given this "Bear suit" by the world's creator.
This suit, made up of the body section, two boots, and two paws, has a whole host of wacky bear-based abilities such as using the white bear glove as a storage dimension, using the bear hood to identify nearby enemies, or even spawning a whole bear-shaped house. There are so many more abilities tied to this superhuman suit it's laughable. But, at the very least, the fact that all the abilities keep with the bear theme is impressive.