Wortenia Senki (WN) - Volume 1 Chapter 1 (Early in the morning)

Zong Shou woke up from a dream and realised that he had time traveled back ten thousand years, to an era before the God Emperor was had appeared in the world.

Wonder Woman: Why are you Superman’s younger brother? Eric replied: On the first day of travel, I, who was also a baby, climbed into Superman’s baby capsule, pushed him out, occupied the nest by myself, and became a “son of Krypton”.

Superman: Why don’t you save the plane? Eric replied: I will not lift things by stepping on the air.

Batman: Why didn’t kryptonite work for you this time? Eric replied: I originally wanted to get along with you as a Kryptonian, but in exchange it was alienation.

Okay, I’m not pretending anymore, I’ll showdown, I’m a native of the motherland. …… This is a story about a man who was mistaken for a Kryptonian with a template of the motherland, but is actually a sinister and black guy who is doing things in the world of superheroes.

- Description from novelbuddy

King Grey has unrivaled strength, wealth, and prestige in a world governed by martial ability. However, solitude lingers closely behind those with great power. Beneath the glamorous exterior of a powerful king lurks the shell of man, devoid of purpose and will. 

Reincarnated into a new world filled with magic and monsters, the king has a second chance to relive his life. Correcting the mistakes of his past will not be his only challenge, however. Underneath the peace and prosperity of the new world is an undercurrent threatening to destroy everything he has worked for, questioning his role and reason for being born again.