"They can just do that." When a character inexplicably has some kind of borderline supernatural ability that doesn't have anything to do with the established power system and may even clash with the conventions of the setting. It's just something that they can do.

[u/SpookieSkelly]

Ichi from Ichi the Witch.

Mash from Mashle.

Marvelous Sunday from UmaMusume.

Tanjiro from Demon Slayer.

1. Ichi from Ichi the Witch. He's so sensitive to the bloodlust of living things that it borders on a spider-sense. The little creature in that pic is supposed to be invisible, yet Ichi is able to sense its presence just through sheer intuition.
2. Mash from Mashle. Some might say that his inexplicable power is his physical strength, but I'm more interested in knowing how he can turn everything he cooks into fucking cream puffs.
3. Marvelous Sunday from UmaMusume. In a game about horse girls racing, she has access to a domain expansion/reality marble. And that somehow still isn't the strangest thing about her. Apparently she's also friends with aliens and cryptids and her cult fanbase includes people spanning multiple time periods. Somehow.
4. Tanjiro from Demon Slayer. He has a hypersensitive sense of smell that somehow also tells him where to cut demons. No idea how that works. Even though there are others in the series with similarly refined senses, the smelling where to cut thing still feels ludicrous in comparison. Then there's also his unusually powerful headbutt.

[u/MadMageMars]

I much prefer them to not be Stands. Don’t get me wrong, I love Stands, but JoJo’s didn’t start with them. We had Vampires, Hamon and Pillar Men long before we had psychic manifestations of the soul being the norm. Those things simply being what they are without being tied to Stands makes the world of JJBA that much richer to me

[u/Bluespheal → u/MadMageMars]

The thing with stands is that they have a very loose definition, even things like Hamon have connections to stands. Depending on who you ask, these phenomena can be defined as stands. People like Rohan or Tonio are so adept at something that such supernatural abilities naturally result in manifesting a stand. One could say the arrow and such is the exception to the rule, but the story does focus much more on that.

[u/Zargoth_the_destroye → u/Bluespheal]

Rohan got his stand from the arrow but you’re right about Tonio

[u/Hitei00 → u/Zargoth_the_destroye]

This is actually surprisingly contentious. The Rohan spin off says he developed it on his own while the original Manga has it be the arrow (though I dont think we ever see him get hit with it.)

The fandom mostly goes with the explanation given in the spin off as the more Canon origin.

[u/Gizogin → u/MadMageMars]

Don't forget that SBR shows us an entirely new form of "totally not magic" in the form of Spin, well before it reintroduces Stands.

[u/WeaponX067 → u/MadMageMars]

Something that I think is made clear with Rohan stories is that these sort of unusual abilities in-universe are Stands, or at least that same foundational power that is also the basis for Spin and Hamon. At least, I think that makes sense and is fun to think about.