I Came From The Mortal World - Chapter 39 - Priceless

Our straight (?) bottom woke up ten years into the future and found himself on the bed of his childhood friend… At the start, the bottom was shocked to his very bones, but he soon quickly accepted this premise and found the whole situation to be rather amusing. Precisely then, the bottom once again went back to his timeline — back to when he and the top were just platonic childhood friends.

Landmines include but are not limited to: Sweet & naive bottom, a president story, logic is dead, slow-progressing romance, the protagonist’s name has too many character strokes, the names are hard to pronounce, too many gay characters…

At the end of the dark 40,000 years, the enemies in the Milky Way launched their final offensive. When the end of the Era comes, the eternal war will come to an end. The human empire has now reached its destined final moment.

But the gear of fate does not end. The fate of the Milky Way will be determined by him and them as it was ten thousand years ago. What will happen at the end of this dark 40,000 years?

- Description from novelbuddy

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

Jacob Steve, an Old Man, died at 116 after living a whole life.

But Jacob always had a dark side, which he always suppressed and hid from others.
However, in the later years of his life, when death was inevitable, he understood there wasn't any point in having wealth, knowledge, or desires if you couldn't have a life to enjoy them.

He became obsessed with fabled immortality and devoted his reaming life to extending his fleeting lifespan, but just like any other failed.

However, he mysteriously got another chance at life and found a way that led to fabled immortality.
But he was also forewarned that the way led to it was filled with blood and darkness!

In the end, Jacob chose it anyway with no way of going back, and it was also the start of his suffering and his icky, brutal journey toward the 'Immortality' he wanted so badly!