My Master Is Super Powerful But Overly Steady - Chapter 235

Parents dead, clan exterminated, body burned, hands mutilated, inflicted with innumerable diseases, tossed into the dump, and even the magic ring with the ghostly grandpa in it has been sabotaged. A reasonable person would roll over and die. Tian isn't that reasonable. And as it happens, neither is Grandpa Jun. A very tough kid meets a very cunning old man. And together, they will shake the heavens. What to expect:-1 chapter a day M-F. Volume 1 is already complete.-2k words per chapter (aprox, some run long) with a longer first chapter.-No Harem-Earned power growth-An MC who isn't a goodie two shoes OR an edge-lord psychopath-A power system based on actual Daoism -Sects, giant monsters, natural treasures, flying swords, spells, talismans, secret arts, and a gentle sprinkling of young masters whose face need rearranging.

After breaking up with his girlfriend, he accidentally acquired a genius system and rose from there against the heavens, becoming invincible..

- Description from Novelupdates

This legend tells the tale of the protagonist, Kuroki summoned to protect the demon king from the hero.

Kuroki, unbeknownst to him, suddenly came to another world. He was summoned by the demon king, Modes. The territory which the demon king overrules was in the midst of being destroyed because of the hero. He had no choice but to bow before Kuroki.

“Please save us, Savior Dono!”

Kuroki nodded, deciding to save the demon king due to an unexpected turn of event.