I Have the Alchemy Emperor in My Head - Chapter 2

This is the tale of an earthling, who transmigrated as a dying third-rate god but somehow rose through the ranks, gaining followers and eventually causing the Fourth Great Apocalypse.

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 aliens came with hostility.
Facing the invasion of aliens, human beings are weak like ants.
So this is the end, the real end.
But there is resistance when there is an invasion.
For some, this is not the end, it is war.
So this is war.
Real war!

- Description from Qidian

She is a top-class spy, a poison specialist, but also a young and cute girl with a sinister temperament. In spite of her sweet and innocent appearance, she can complete any tasks without the slightest hesitation. One day because of an incomplete black magic, she was sent into the body of a girl who was deemed as a good-for-nothing. What kind of change will she bring to this continent?

A Prince said with bitter hatred, “I thought she was weak and easily bullied, therefore I broke off the engagement. I really didn’t expect she is such a shrewd girl. I made an error of judgment.”

The Crown Prince deeply sighed, “She is such a sexy evildoer! Obviously, she has a frail and tender body, but I am not able to overwhelm her…”

Finally, an Emperor hit the nail on the head, “She is just a bit two-faced!”

She answered, “You’re just a big pervert!”

The Emperor carried her into the room and said, “You are predestined to be mine! A two-faced girl and a pervert are a perfect match, right?!”

- Description from Novelupdates