While Others Cultivate, I Use My Multiverse System - Going premium, current delay, basic promised info:

Mu Yu, who had just started university, unintentionally downloaded a mysterious hand tour and was brought to a strange and bizarre world, becoming the first player of the ‘Mystical World’.

By chance, Mu Yu joined an ancient sect that had declined for a thousand years. He successfully repaired the sect’s supreme technique, the Secret Manual of Space and Time, and became its spacetime descendant.

After three months, players officially logged into the Mystical World game. Mu Yu was already the pride of South Sky.

Two years later, when the players had grown up, Mu Yu had already become the most dazzling Saint under the starry sky.

….

At the foot of the Misty Cloud Mountain, a young girl in a white dress nestled in Mu Yu’s embrace as she cried, “I, Nalan Yanran, would rather die than marry that young master of the Xiao family. I only wish to marry you in this life.”

“Ding!” You have successfully triggered a 3-star mission! to help Nalan Yanran go to the Xiao family to end the engagement! ”

“Wait a minute, this script isn’t right. Can’t we just not do it?” Mu Yu felt like crying.

“Either way! Either die! ” The System pulled out a 10m long broadsword.

“Stop, can’t I do it…” Mu Yu submitted.

- Description from Novelupdates

A genius talisman practitioner is reborn as a seven-year-old girl! However, her innocent appearance belies her vicious personality.
In the remote countryside, the Crown Prince runs into her, beating up her enemy. She is indifferent, but it’s love at first sight for the Crown Prince!

“Not good, Your Highness the Crown Prince, Her Highness the Crown Prince Consort used an immobilization talisman on His Majesty the Emperor, and His Majesty is currently eating dirt in the main hall.”

“Isn’t that normal? Who told that dog emperor to provoke my wife? I say it’s a job well done! Pour a bucket of ice water on him to cool him down!”

- Description from Novelupdates

This story is centered around the man named Yi Ji-Hyuk, who has spent 1000 years in a Medieval Western fantasy-like world before returning back to the modern-day Earth. When he returns, he finds that his home is facing monster threats, and that humans with superpowers have appeared to protect the innocent people of Earth.

Sirens: a name derived from an ancient creature, used to describe those who could charm, lure, control, and heal others by singing.

Subjected to live the life of a siren, Aria had experienced, seen, and heard many horrific things. Broken beyond repair, Aria resigned herself to death, when suddenly…

The Grand Duke, Lloyd Cardence Valentine, arrived and whispered, “Should I kill everyone here?”

“If you need me, just call me. Your song will always reach me, wherever you are.”

In the end, Aria called the devil, bringing death to all those present, along with herself.

“Let’s fall down to hell together.”

And with that, Aria breathed her last and died… only to return to her 10-year-old self.

Now that she had a second chance at her life, Aria was determined to change her fate, as well as the cruel fate of her saviour, Grand Duke Valentine.

And so… Aria proposed to him with a marriage contract.

She sold her soul to the devil and vowed to protect him.

The young duke took the contract from her hand.

“So, where should I stamp the seal?”

* * *

“You said you’d divorce me within 10 years.”

The grown-up villain leaned in, hovering his head before he kissed her tenderly over her crown.

“Now that we’re adults, we should sign another contract.”