Longevity Martial Arts: Grinding Experience in the Chaotic World

[You have transmigrated, named Gu Sheng, and are a farm boy.][This is a dynasty in chaos, where demons and monsters lurk and bandits run rampant; as someone at the bottom, you face hellish survival difficulties.][You decide to lay low.][You awaken a mastery panel.][You breathe a sigh of relief, you can start grinding.][You grind Chopping Wood to Perfect, chopping bones and breaking tendons with ease.][You grind archery to Perfect, becoming a godlike archer who can hit a louse at a hundred paces.][You learn the Iron Stone Fist, set foot on the path of a Martial Artist, and grind it to Perfect, with punches as heavy as a million pounds.]……[You learn the Longevity Eternal Youth True Art, greatly extending your lifespan, giving you more time to grind, and greater hope to lay low.]……[You grind to the limit, steadily laying low, and one day you suddenly realize, you are invincible.]