Chapter 1: A Drive to Protect

Saitama McGarrett was just a normal child, but he carried a big secret: he was the love child of the Symbol of Peace, All Might. After his mother was killed by All for One, Saitama was raised by a hero by the name of Maverick, whose real name was Boris. However, after One for All had activated, Saitama nearly died. Desperate, Maverick had called upon the Medical Hero, Doktor, to help save Saitama. As a result, the two managed to save his life by transferring all his memories, and his soul, to a cybernetic body.

With his near brush with death, Saitama had an even bigger reason to become a hero. However, he now had an edge since he had cybernetic enhencements. He no longer had One for All, but instead had his mother's quirk: Blade Summoning. That was when he learned of his Samurai lineage, and relation to the Lightning Samurai Hero, Raiden. He soon learned of Raiden's dark past, such as his time as a villain known as 'Jack the Ripper.'

Raiden had told Saitama everything in a dream, including about the friendship/rivalry with the Swift Samurai Hero, Jetstream, whose true name was Sam. He even told of Sam's legendary blade, Muramasa. Afterwards, he trained Saitama in the different forms of martial arts and sword techniques that he knew. At the end of it, Saitama had gained a newfound knowledge, and vowed to fulfill a promise. However, it would have to wait until he got to high school.

One day, when Saitama was at school, an unknown group of cyborgs had attacked. They spoke about a "Quirk Purge" that would take place in the school, and that they would start with any who revealed their quirks. One kid in Saitama's class named Bakugo tried to blow them away, but was caught. The group then said they would start with him, but Saitama intervened and called upon Muramasa to dispatch of them while using what Raiden had taught him.

This is the story of Saitama's rise to becoming the Rebirth of Raiden.

Lightly based on Metal Gear Rising: Revengeance, with light crossovers.