MTL - Different Dimension Game - ~ 1-point summary written in 1.18 million words

She roused from a pool of blood, vowing to exact retribution on those who had harmed her.

The strongest Hero in history, Nakamoto Keisuke.

He was summoned to another world in the spring at the age of fifteen years old, and when he successfully defeated The Demon King, he was already thirty-two years old. He had finished his role in another world and returned to Japan, but the reality that had been waiting for him was, “Middle school graduate with seventeen years of blank period” label. He couldn’t find a decent job and had no choice but to spend his days working part-time.

Before such a Nakamoto, a beautiful girl who self-proclaimed had come to return the favor, appeared. “I’m the reward for Hero who had defeated Demon King”, said Angelica, a girl who came from another world that persistently tempted Nakamoto to make her his wife. Together with a high school girl who looks like Elsa, his beloved girl that he lost in another world, Nakamoto with his cheats skills got caught in a harem life.

The end of all worlds approaches.

The Demon King Order harvests lives from all manners of living beings.

Within this darkness full of despair,
A single person escaped from space-time, returned to before the world collapsed, determined to change the fate of the past.

But as time pass, he gradually finds out that the Apocalypse isn’t quite as simple as he thinks…

- Description from novelupdates

In the steampunk world, races are mixed, and all spirits coexist. This is a different world that worships Iron Armored City!

The smelting furnace provides kinetic energy, heavy weapons protect dignity, and armor is the strongest protection. Every mobile ‘Iron Armored City’ is an independent force.

Every ‘Iron Armored City’ is a hunter driving in the wasteland, and likewise, all Iron Armored Cities are prey in the eyes of the stronger!

- Description from novelbuddy