Elf Tensei Kara no Cheat Kenkoku-ki - Chapter 10Book 4: -1: Compromise

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

Fate and destiny; no one can foreshadow the terrifying challenges on the road to the Pure Land. Instead, one may unearth the evil within the road of light towards paradise.

A King’s Holy Sword, bringing light to the darkness,

An unyielding soul, igniting the fiery hope of the world,

As his soul awakens, the youth fiercely battles the gods of darkness and evil,

As the surging dark clouds gushed out like a phantom, their conflict swept the world like raging tide!

The clash of darkness and light, a massive war on the verge of exploding,

The decisive battle of gods and deities rewrite the creation of the world into one destructive epic!

- Description from Novelupdates

Vahn was an atypical youth. Due to a rare mutation, his blood had the potential to target and attack ailments within the human body. Touted as a universal cure, people had elevated his status above the norm and given him the classification "Panacea". In the media, he was hailed as a great hero who would usher in a new era or human wellness. However, behind the scenes things weren't so bright. Being a unique individual, Vahn spent his entire youth locked up in a lab with various scientists and research teams using his body and blood to perform endless amounts of experiments. The only solace in his suffering was the various anime and manga made available to him between experiments. He often imagined himself as the protagonist in a world of his own, finally in control of his own destiny. For years he nurtured this desire, until at the age of 14 he died when an organization had tried to kidnap him from the lab...

Arthur Grail, a hardcore player of the VRMMO Trinity Star Online, woke up one day in the body of Gerard Astoria—a petty villain fated to die before the main story even began. To make matters worse, Gerard's death was a crucial event in the game's narrative. If he didn’t meet his predetermined end, it could disrupt the story entirely, leading the universe toward one of the countless “bad end” routes!Unwilling to leave his fate to chance, Arthur decided to take matters into his own hands—recruiting the “player” as his partner to help him clear the game and rewrite his destiny.But wait—“Why is the player not a dude but a sharp-tongued beauty instead?!”Follow Arthur's odyssey, filled with trouble at every turn, as he works to uncover the mystery behind his awakening in a universe eerily similar to Trinity Star Online's setting, all while trying to save the entire universe… without forgetting to enjoy himself!