Kyoukai Senjou no Horizon - Volume 7C, Chapter 75: Approacher of a Place of Reminiscence

Wang Yi gets a key, opening a door in 2022 will lead to 1982, and opening a door in 1982 will return to 2022.

Two very different great eras appeared before him:

Abundant dietary protection, developed industrial products, miraculous medicines, and explosive information, this is 2022.

Simple folk customs, rich wild resources, scattered antiques, and treasures of the age, this is 1982.

Traveling between these two eras, Wang Yi didn’t think much of it, he just wanted to live a good life.

- Description from novelbuddy

This is a story about a badass,

A young man dies tragically while trying to stop a robbery—only to awaken in complete darkness, lost between life and death.As his memories return, he discovers that he’s been reincarnated into a new world brimming with magic, Soul Weapons, and mystical powers. Reborn as Ares into a loving family, he quickly realizes that this world is far from peaceful. Armed with an SSS-Rank Trait and a Unique Ability, he faces every challenge head-on as he searches for his purpose in this strange new reality.

What if you spend your whole life like a vegetable in a hospital bed? Only being able to speak and listen. Just that. Would you go crazy? Unbalanced? What if it was all the fault of a degenerate madman looking for his parents' inheritance? Would you be angry? Would you be mentally broken?That was Kayden's life for 20 years and as quickly as it started, it ended, but luckily for him, reincarnation existed and by some miracle, he still had his memories of it. And....his new world had...magic.In the first moment of consciousness, Kayden made a promise to himself, in this life, he would achieve everything, he would reach the height of power, he wouldn't give a damn about women or money, futile things that would condemn him to mediocrity, his focus was to have the power to rule his destiny, this time he would not be a slave to his own life, he would be a monarch.