Stardust Crusade (JoJo's Bizarre Adventure Fanfiction)

Chapter XX: Super D Duper Star, Like a Star, is a Challenge for Saitama

Jotaro stayed inside a cylinder glass in the middle of 15-meter-radius room.

Vegeta then battles Star Platinum, teaching Jotaro new moves. Training Regimen, Exercises and Martial Arts.

Vegeta even teaches him...

Final Flash.

Jotaro makes Star Platinum spread his arms out as he charges energy.

He puts his hands together and shoots Vegeta, who dodges.

Vegeta laughs.

Vegeta: "Workout finish, boy!
Your Stand survived ten thousand times Gravity! AMAZING!!! AHA HA HA HA HA!!!
You can become stronger by one thing... PRACTICE!!!
Like the Caped Baldy.
He cheated because he's frail."

One Punch Man became strong, because of a limit. 

A limit is a barrier that people can never break unless their desire is great enough.

Daisuke Saitama did not want to do this for himself... to become stronger... He did this for one thing. For the good people of the world.

Saitama is not driven in selfish desire, but is driven by others.

Unlike Goku, who wants to get stronger because it excites him, for Saitama, his determination and obsession with becoming stronger is driven for and by others.

Saitama was born frail, and was mutated by breaking his limiter.

Saitama is also known to practise 100 push-ups, sit-ups, and a ten-kilometer run every day... even nowadays.

Saitama is already in his most powerful form, Limit Breaker.

However, he isn't in his full power.

Saitama never used his full power, as boredom entered his heart forever. Boredom that he will never face any true challenge.

Boredom and Dullness in one's heart.

Saitama, will never use his full power.

Until now...

Vegeta gives Mista a Galactic Patrol Blaster.

He uses Sex Golden Pistols to shoot the blaster's ray and redirect the bullet.

Mista smiles.

Mista: "Cool."

Vegeta: "You can kill almost anything with that blaster. It was designed by Freeza to kill Super Saiyans."

Mista: "Hm....
Hey, guys... where's Saitama?"

Mob... a boy who had nobody on his side his entire life, until he found his hero...
Saitama.

Mob opens the door as Saitama is still exercising.

Mob: "Oh...
Hey, Mr. Saitama!"

Saitama: "Oh...
Hey..."

Saitama does 100 squats.

Saitama: "This is a new training regimen I've decided to try.
Squats."

Mob sits down with Saitama.

Mob: "So... Saitama...
I've been meaning to ask you....
How do I control my-?"

Saitama: "Limit Breaker, right?"

Mob sighs.

Mob: "Yeah..."

Saitama finishes his squats.