Vampir Lord: Erotic RPG - Chapter 7 My First Day In Another World.

Having a rough life growing up, Wang Tong had numerous dreams of living a better life. However, his alcoholic foster father sells him off as a space settler of the distant planet Norton for some pocket change. Soon after his arrival, the Zergs overran the planet and obliterated its defenses in a matter of minutes. What awaited Tong on Norton was more than just an unbearable environment – its gravity alone was five-times stronger than earth – there were also swarms of bugs, constant hunger, thirst, and desolation.

While he lives a year of total carnage and survival, humanity’s Confederation eventually overcomes the Zergs on Norton and the powerful survivor Wang Tong is given a recommendation to a once famous, but now dying military academy where he begins his life anew.

- Description from Novelupdates

Luo Ling, an expert in the art of disguise, was bound to a System and was eager to begin his task.

As a result, before even successfully completing a mission, he got married!

At a 36 degree angle, Luo Ling sorrowfully looked up into space: “Tong’er, tell me, do I still have a chance to free myself?”

System: “… Your man is behind you.”

Luo Ling: “!!!”

The person who arrived, gathered Luo Ling in his arms, hugging him from behind as he said in a bewitchingly dangerous tone: “Based on your thoughts, it seems that I have not given you enough love. So let’s proceed in exploring ways to continue a new life.”

- Description from Novelupdates

On her wedding day, she was humiliated; her status as the legitimate wife was instantly changed into that of a concubine.

Living a dual life, Lucas was a meek boy in school and a Wire Knight on the Internet at night. Surprisingly, he's asked out on a date by one of the most beautiful girls in school.

However, the date ends after a bizarre sequence of unfortunate events, he gets isekaid into another world.

Lucas received a rebellious system and some strange pills as rewards which released the dormant evil within him. He has to control the rooting darkness coming from the previous protagonist of that place and learn how to control his power.

The system promises to fulfil one wish if he will win the game he was sent to. This motivates him to help his sister to get better and become healthy again, he must obey the system and win the game to be granted that wish no matter what.

To form a team with another human, an elf and a so-called 'sex machine'. Lucas has to collect all the avatars and learn how to control them, wield the weapons that were given to him and win the tournament of the place by killing the black wizard.

Time is quickly ticking and there's a huge mess for him to reverse. Starting from his date who suddenly was transformed into a dragon!