Saitama and Mob, created by ONE, possess more differences than similarities.
ONE, the talented creator of the famous anime/manga series One-Punch Man and Mob Psycho 100, views the main characters Saitama and Mob as opposites, despite clear similarities and contrasts with conventional archetypes.
One-Punch Man introduces Saitama, the strongest being on Earth, now feeling disillusioned with his own power. Mob Psycho 100 follows the young psychic Shigeo 'Mob' Kageyama, who desires a normal life despite his extraordinary abilities.

Saitama is renowned for his one-punch knockout ability. Even the Dragon-level monsters of the Monster Association pale in comparison to Saitama's might. Mob possesses incredibly powerful psychic abilities, leaving opponents with no chance. While both possess immense strength, Saitama is lazy and foolish, while Mob appears frail and emotionally unstable.

In an interview with Weekly Shonen Jump, ONE states: 'In contrast to One-Punch Man, the main character of Mob Psycho 100 is very nuanced emotionally'. The author observes these two characters at opposite ends of the emotional spectrum, a facet that makes them uniquely captivating in the story. This perspective illuminates the unique approach ONE has taken with his two works.

While One-Punch Man primarily focuses on Saitama's hero career, Mob Psycho 100 delves into Mob's relationships with other characters.
Ultimately, the creator's perspective on the two spiritual offspring as opposing extremes is to broaden the perspective of fans, who often concentrate more on character similarities than differences.
In the end, One-Punch Man and Mob Psycho 100 are undeniably remarkable works. Understanding how they differ allows the audience to appreciate the author more deeply and profoundly.