Cultivation: Being Immortal - Chapter 410:

The world ended, seven days of earthquakes, volcanic eruption and then came the meteor storm, bringing something worse—mutation.Now, survivors are group into Shifters, mutated humans and normals.Ava Zhang was supposed to be a Normal. Useless. Disposable.Thrown into a military-controlled bunker, she is sorted into Level Three—the bottom rank, where the weak are left to rot. Starving, overworked, and surrounded by desperate scavengers, she realizes that in this world, strength decides survival.But Ava isn’t as powerless her hidden System activates. The Blueprint System—an ability that lets her design and invent anything, from weapons to high-tech defenses.

The blacksmith Anvil created weapons alone in a ruined world.

He came across a community, a hero universe, where there are heroes of every dimension.

All the heroes wanted his weapons,

All the monsters hated him,

All the world blessed his existence

however nobody prevented his death.

Decades later, a dimensional invasion started on earth.

Kang Shin-hyuk, a boy who can’t use mana inherited Anvil’s VIP ID and memories.

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…

- Description from novelupdates

In a Fantasy world in which a young girl with the Divine Protection of the Hero battles against the Demon Lord. In that world, Red, the elder brother of that young girl Hero, possessing the Divine Protection of the Guide which only grants a high initial level, fought in the initial party of the Hero.