MTL - This Is My Primitive Tribe - Chapter 72 Vigorous Mushroom and Divine Mushroom

An alien race invaded the Earth on June 6, 2128. At the midst of this war, many nations allied with the alien threat and the war nearly wiped out the rebelling humans of the planet. At the edge of mankind's survival, the United Nations Army launched its forces to eliminate the immediate stellar threats that loomed over Earth.

General Seeker Carlean, commander and leader of the mission, risked and gave his life to destroy the immediate stellar threat. The battle was won though Earth lay in ruins. Perhaps mankind will live to see a few years of peace before the alien threat returns to wipe out their existence.

At the immediate aftermath of the stellar battle, the fallen Seeker Carlean awakens and finds himself at aged 17, living the peaceful life he lived 16 years before he died.

So begins a new game in the battle for humanity's survival.

Earth Immortals are cultivated from a blessed land.

Kawaki, who was born in the dragon vein of a planet (Altana), first met Umibozu who was traveling in the universe, and his girlfriend, Kouka.Later, he came to Earth by accident and met the teacher who affected his life —Yoshida Shouyou.He also met a group of friends. The most conspicuous among the group of friends is a fool with silver hair and naturally curly hair, a short man with purple hair, and a little devil whose catchphrase is “Not Zura, it's Katsura!”Gintama Doujin, not transmigration.

As a promise, he went out into the world as an assassin. 3 years later, after becoming the Supreme Assassin, he gave up on everything he had and returned to the ranks of ordinary people. But one day, Kismet, a mystical game created by the National Research and Development had appeared.

Enigmatic hands, spectral frame, and one cunning strike just like the swing of the Grim Reaper. The Supreme Assassin takes on the mystical world, and how his legendary tales sets off, progressively ascending the altar to becoming the best.

- Description from Novelupdates