Suterareta Yuusha no Eiyuutan - Story 4-5: 『Break Through』

This is a story about the protagonist getting the system, going crazy in the biochemical apocalypse, producing aircraft and tanks, destroying zombies, saving good people and killing bad people.

- Description from novelbuddy

He was the continent’s strongest and most revered alchemist, Ye Zifeng. He was under one person and above millions. However, due to an unpredictable event, he had died. After his rebirth, he had become the supertrash of the Ye family and suffered disgrace. To make matters worse, he had an argument with his fiancé that led to the break off of his engagement. In this second life, he will work to change his own destiny. He vows to return to the peak of the world, trample on those who laughed at him and rewrite his legacy!

- Description from Novelupdates

What would you do if you could shuttle the plane?

Gao Linhao got an artifact that can shuttle the plane, so he reached the pinnacle of life, and became an existence beyond everything, just suffering from the unrecognizable planes that Lin Hao had given to evil!

Ji Linhao said, “I want to change as long as it makes me unhappy!”

- Description from Uukanshu

The happiest thing in the world is to be able to amend what you have done wrong. She who acted willfully because of a game, was reincarnated into a time when she still had her parents’ love.