I saw one post in these forums which was about dark powers but there were no replies under it. I too love the 'dark' and hidden past thing in manga and anime. I'd wish to have some recs. Finally someone had pointed out and I'm not The only one with the filtered genres.
The user had written the following and I'd already checked out all of them.

   So, I've seen anime (s) and read manga (s) where the MC is a   
    normal person or an abnormal person in the beginning in terms   
    of powers but in the end, or later, kaboom- and they've some    
    dark secret to them which makes them super strong n   
      awesome, cool.  
         D. Gray man- Allen  
         Owari no seraph- Yu  
          Pandora Hearts- Oz  
          Black Clover- Asta

          So I really like this dark power+ mystery MC+ cool bros + that one trait of MC which stands out.  

So I really want some recs. Plz help an otaku.

Since you are looking for an archetype there are many mangas that fit the description that are ongoing or axed ,(I would recommend you also search for seinen .Since realism and more mature plots tend to have those type of characters).

Most of these start with some comedy but they fit in your categories and are complete :

Helck
Trigun Maximum
Spirit Circle
Hoshi no Samidare
Psyren

You might also like Charlotte anime .

I hope this was of use.

It's mostly shoujo, but From Far Away.

Like cute things. 🐇🌸

No,Spirit Circle and Hoshi no Samidare are published in 'Shōnen Gahōsha' the rest of the titles I and the OP put are shonen ,but all these could perfectly fit in a shoujo magazine (adding the shonen filter might actually filter out things he might like) .Since strangely enough a manga being shoujo or shonen depends on where it's printed. 😛

Overly Sarcastic Productionsはこれをカバーし、「超強力な悪の味方」とダブっており、全体のアーキタイプというよりはむしろトロフィーとして捉えています。レッドがそれを提示する方法は、文学的な参照として素晴らしい働きをします。