The God of War Who Regressed Level 2

[NO. 4212. ‘Humanity’ was defeated in the relegation war.] [The obliteration of mankind begins.]
After the last survivors on Earth failed the final mission and perished, he was given a chance to return to the ‘first entry point’ before the world was doomed to end.
-I, Sejin Yoon, have decided to live as a Japanese from this point forward!
– From now on, please call me Ryuhei Ito.
As soon as he opened his eyes, the first thing he heard was the news of his brother-in-law’s betrayal, the “current king of swords” in Korea.
“…that’s it, I’ll take care of this bastard first!”
Watch the relentless steps of the Korean martial artist, Seong Ji-han, who will save the future from destruction and achieve peace with his thorough planning for a thorough revenge!