Skeleton Knight, in Another World - Chapter 20Volume 5 -

Legend says, that there is a great demon, who is the human kind’s public enemy. He is the galaxy federations’ nightmare as he wanted to conquer the whole universe. On the first day, he completely took out the human fleet, plunging them into disorder. On the second day, he declared that he will wipe out the whole federation. On the third day, he declared——that the hero who shot him in their previous battle must marry him, or else, he will destroy everything.

The galaxy federation president and the council members had a long meeting after that. They decided to dispatch a soldier, Wu Xing Yun, and marries him off to the arrogant demon. Wu Xing Yun was once a hero who fought for the nebula, and henceforth, he was tasked—— for the sake human race and the universe’s peace, to eliminate mistresses, settle his matters with the mother-in-law, and fix the man’s crooked ways.

Wu Xing Yun was very perplexed when he asked his commanding officer: “Sir, why did it have to be this way?”

Commanding Officer: “Soldier, bear in mind, that this mission of yours, is for the sake of the universe and mankind’s happiness. You must hold on to your husband, and fight other mistresses! Do you have the confidence to accomplish this task?”

Wu Xing Yun, stood straight, saluted, and instinctively replied: “Sir, yes sir! I will accomplish this task!”

- Description from Novelupdates

In a world where Magic reigned supreme, Ruling over the Mythic Elements were the Holy Magicians of the Sacred Elements.

A young prodigy, Gabriel was selected as the Holy Priest in the Church of the Magic of Light. He was the youngest mage to awaken the most coveted element of light; his future was supposed to be bright... But one day, he disappeared as if the darkness had swallowed him up.

As Gabriel walked on the thin line between life and death while fighting for his life, something came in his life... Something that was going to change his life and the world forever...

Step on this unforgettable journey of light and darkness that transcends boundaries of space and time like never before...

Alex was an ordinary teenager—until the day he discovered his ability to drain energy from the dead. With powers rooted in death itself, Alex hides his necromancy behind a normal life, secretly entering deadly portals to fight monsters and earn money. But beneath the surface, a darker truth lingers—his parents's death and his powers are linkedAs he harnesses his necromantic abilities, draining the fallen to grow stronger, the weight of his power begins to take its toll—and the line between the living and the dead starts to blur.With enemies closing in and betrayal around every corner, Alex must master his growing abilities before they consume him—or worse, before the forces hunting him claim everything he has left.When death becomes your greatest weapon, how long can you survive before it turns against you?---

This novel is also known as From The Start, I Traded A Galactic Warship

After getting a trading platform three thousand years later, everything in the world has become an antique, worth a thousand gold.

But it was also learned that three years later, aliens invaded, human beings fell, and the dark starry era began.

In this era of unprecedented change in tens of thousands of years.

Shen Shi decided.

First trade a space battleship, and then talk about it.

then–

Battleships come to the world from outer space! Global shock! Starry Sky Era, open in advance!

- Description from novelbuddy