Isekai Yururi Kikou ~Raising Children While Being an Adventurer~ - Chapter 502:

Yohan wakes up ten years in the past, back when he still lived with his uncle and hadn’t yet lost his parents’ massage parlour. With a strange book filled with wellness techniques in his hands, he decides to live differently this time—more aware, more purposeful, and maybe even more fulfilled.

Suddenly a high school student Subaru Natsuki has been summoned to another world on the way back from the convenience store. With the biggest crisis of his life being summoned to another world and no sign of the one who summoned him things become worse when he is attacked.

Within the virtual world of “Avalon Online”, Finn, or otherwise known as “Echo” within the game, was one of its greatest players. After logging off from a long session, however, he notices something awry outside of his apartment.The streets were flooded with chaos, screams echo through the night, and hell is loot loose. Monsters from Avalon Online are running through the streets, wrecking havoc. In the midst of this hellish awakening, Finn is greeted with the one gift bestowed to humanity in this dark hour:[...Assessing life experience…][Assessment Complete][Name: Finn Thorne][Age: 20][Designated Class: Assassin][Starting Level: 5][A [Legacy System] has been bestowed to you for your accomplishments within Avalon.][Assimilation System Awakened.]In this twisted turn, as the world as it was once known is gone with the arrival of magic and monsters, the remnants of humanity must level up if they wish to survive.Finn is left in this dark, hopeless apocalypse, using his own experience from Avalon Online to best survive what seems to be an impossible task.

This world is sick; both Immortals and mortals suffer from a stubborn ailment known as Longevity.Under the influence of Immortality, various Cultivation Techniques evolve rapidly in grotesque and inexplicable directions.[Fetal Period: A baby is born with shriveled, powerless limbs.][Childhood: After 20 years, the Internal Organs completely decay.][Weak Crown Period: At 50 years, the flesh dries and withers.][Thirty Years Old Stage: After 100 years, the blood runs dry and gives birth to mutations.]I am an Immortal Seeker, and also one seeking survival.