Hey all,

Looking for any manga, where the hero/MC goes against the difficult enemies, while he himself and his team DO NOT HAVE ANY SUPERPOWERS.

Something that's more rooted to pure underdog.

Oh, and if the story line is completely unpredictable (i.e: MC loses, unexpected deaths), even better!!

There's just too much manga/anime these days where the MC is so conveniently imbued with superpowers out of nowhere. Hated those...

😎

An intriguing action manga with a protagonist who wins without useful/OP abilities doesn't exist. 😮
However, an intriguing action novel that have multiple main characters that cannot realize their dreams with just brute strength does exist.
Try Mushi-Uta (Novel) if you can handle a few deaths. Note that the anime and manga adaptions are trash.

"You are weak, from the moment you could only use your life as an excuse for committing crimes, you insulted that very life. You didn't notice, you were afraid of noticing, and you went around destroying everything that could make you notice, but you have also crushed your ability to ever gather respect." -Shokuhou Misaki

First off I've searched through all my lists with in the advanced genre search thing with "Action - Weak Male Lead" and this is all I've found that is even somewhat close to what you want.

Kaibutsu Oujo I wouldn't call this one unpredictable as it is a shounen comedy, but it's entertaining. Has blood and guts in it at the very least. Was one of my favorites when I was younger. His team DOES have superpowers though.

Onihime VS As one would expect of LIM Dall-Young. Notorious for rushing / axing / hiatusing everything and lots of big boobed characters. Nonetheless the story is interesting. Read all the available chapters years ago and never bothered finishing it. Again, team has superpowers. Shounen, boobs. Looking back, I wouldn't really recommend it to anyone... but whatevs, here.

Over Steam I haven't read this in a while so I don't remember exactly what goes on but if memory serves correctly... Main character has some special ability? (maybe 😕 ) but is weak, mainly getting things done through being clever. Going to re-read this right now because I remember it being a really interesting story. Serious story with actual unpredicted twists. Recommended.

Eleven Soul Wasn't sure if I should recommend this one as it isn't translated and I haven't actually read it. On wish list. Description seems to fit what you actually want though. Worth looking into if you understand Japanese.

Mx0 maybe. Shounen with a school setting. Very minor spoiler:

While the protagonist gets something like a power, it's different from the other ones, so he has to deceive.

Take note that it got axed at ch. 99, with a lot of things left unresolved.