hey, how's life? I hope you all are doing good  
I am searching for novels with realistic characters and cool superpowers, I don't care about the plot or the world-building part. It doesn't matter how bad the plot is I just need you to recommend me a novel in which characters feel like real people who do not have fixed personalities. For eg:- in many novels, if a character is arrogant then the authors will show him/her as an arrogant person throughout the novel irrespective of the circumstances. In my opinion, a brave person can turn into a scared cat depending on the situation. 
For eg:- the perfect run, shadow slave(it's on webnovel tho), the oracle paths(webnovel) or like steven in moon knight he wasn't ok with helping marc but he still helped them to find the tomb.
Ik it's a very vague or unclear(sorry, I can't remember the word ) thing I asked for but if you have a novel in mind then do recommend it. 

Well, superspeed is a pretty cool superpower in theory. Wanna see how having it might realistically go? ^^

Worm
Really cool super powers and system for getting said powers. Also some pretty neat and creative uses for said powers

Ward
The sequel to Worm

Tautology
Mc has an absolutely fascinating power

Good character? Subjectively yes. 

Cool superpowers? Absolutely yes. 

Self promotion bias...? Maybe.

Self plug here. Im writing a story thats a few chapters in, each character is based on someone i know  and the problems you have is something i want to activly avoid as i write more. Someone who can be kind can also be ruthless, and vice versa is other situations.

The series I just started fits the description you're looking for. It has world building and a super hero. I recommend at least reading the first 3 chapters to get a feeling of the series. If you want feel free to comment and review. 

I second the reccs on Worm and Millisecond above!

If you end up liking Worm, I am also writing a story in a similar vein: No Heroes There

Starts sliding Descent and Cry Wolfe onto the table.

Well, you could try Dr Z if you like sci-fi.  Or pulp.  Or zombies.  A couple reviews mention realism in the setting, or the zombies.  The powers are not quite super, but they're not normal either.  One of my betas called it a space fantasy with space wizard fighting space zombies.  

From my reading list/read later/follows (some of them I read, and some I didn't but sure do sound interesting):

https://www.royalroad.com/fiction/57644/the-seventh-spirit

https://www.royalroad.com/fiction/55593/order-slayer-modern-litrpg

https://www.royalroad.com/fiction/55914/fulcrum-season-one

https://www.royalroad.com/fiction/55927/the-newt-and-demon

https://www.royalroad.com/fiction/44494/awakening-prodigy

https://www.royalroad.com/fiction/53733/channelers

https://www.royalroad.com/fiction/54672/300-moons-till-disconnect-gamelit

Hope you find something of interest!

My story has people with super powers (speed/agility, strength, regeneration/precognition, telepathy, elemental/particle manipulation, and empathy - not all of them at once, each race has its own category) although the focus isn't always on the fact that they have super powers, since it's so deeply ingrained in who they are/their lore. My characters are traumatized early on in life, and so one is quite downtrodden and morose, and the other may have questionable morals/viewpoints but is ultimately doing her best. There is a supernatural element that becomes evident later on. Maybe this is for you, or maybe someone else. :)

Does Magic count? I've got some characters with interesting special spells.

My story Providence has an emphasis on character and their relations, so maybe that is up your alley.

Second the rec for Milliesecond. 

My story, Solar Flare, is a multi-POV adventure with phenomenal superpowers and smooth action. A whole world dies, leaving a sole survivor. The survivor wields the most powerful weapons in the universe, in a lineage that goes back to the dawn of time, but finds it wanting. In search of help, this survivor brings this life-ending plague with it. This survivor meets her successor there, and it becomes up to the successor to fix the universe.

I've been pleasantly surprised with two that might fit what you are looking for.

Tower of Jack - Multiple times the MC straight up runs away from the enemy. He freezes out of fear once when fighting another big boss. He levels his points like a person who isn't a gamer or LitRPG reader, drops potions and valuable weapons, cares little for the nuance of the world. It's pretty funny actually and feels very human at times.

Paranoid Mage - MC just doesn't go the typical perfect run route. When offered the opportunity to learn magic at the hands of the masters he turns and runs and figures it out on his own. He messes up, gets tracked because he doesn't know enough, misses details because he doesn't have formal training. I like the humanity in the errors.