MTL - King Who Will Cross - Chapter 6 Is this what it is?

The end of the world is full of crises, but Su Chen says not to worry because he has the Red Alert System. That’s how confident he is. You say you have a lot of weapons? Sorry, I have more weapons than I can use here. Let me introduce you to the weather control device. You say the mutant beasts are very powerful? No problem, I have a way to deal with them…

Michael, formerly a military veteran turned mercenary, was living quite a peaceful and slightly eventful life. That was until an accident happened that caused him great misfortune, rendering him unable to continue being a mercenary. After that point, his life spiraled into that of an alcoholic, eventually leading to his demise. Before he died, he saw something odd; it was a blue hologram with the words ’Do you wish to start anew?’ Michael readily accepted and was thrust into a fantasy world with a mysterious system companion that seemed to be hell bent on making him the best healer in the world. However, as he began unraveling mysteries, he found out his identity was not as simple as it seemed.

Imperial soldier Suldak Helansa joined the infantry regiment of the Grand Duke Newman in Bena province, participated in the Warsaw plane war, and rescued a young man in the forest battle. This qualified young man suffered some injuries. Injured, still a mute, Suldak brought him into the barracks, and what we are telling is the story of this young man of unknown origin…

- Description from novelbuddy

When the land was occupied by demons, people had no choice but to flee to the sky. After transmigration, Ricky found that he had become the City Lord of a Sky City. He quickly became familiar with this new world and established a clear direction for survival, which was to resolutely engage in farming (kingdombuilding)! He would farm (kingdombuilding) diligently, develop vigorously, and then gallop through the skies. If anyone disagrees, then launch a great sky battle. Or a war!