MTL - The World That Tao Rules - Chapter 110 Asked about the seal

Crying blood and tears, she pledged a poisonous vow. The gods did not fail her. She was sent back to a decade ago. The legitimate daughter of Jiang family returned from hell.

“Heaven's Taboo Doggy Technique”Living his life as a cripple, Xuan never expected anything good in his life; however, the day he discovered a secret library in his sect, he was able to walk into a parallel world.A different world, a modern world of cultivators and his world.The library of taboo techniques awaits Xuan again: the milking technique, doggy technique, dual technique, or sword art technique—every technique in one library.He can now use every technique to boost his cultivation above the gods themselves. Goddesses want his immortal white juice, mothers want his body renew techniques, step-siblings want his meat raw. Xuan's body was the pinnacle of taboo in both worlds.The fucker of mothers, stripper of daughters, and the founder of all techniques—it was only a matter of time.

The Empress who dies in torture, An Rushuang is her name. After she wakes up, she finds herself has time-travelled to when she was twelve years old, but she would turn into Major General’s white horse at night. He is a general who orders about the winds and clouds on the battlefield, and she is a little girl lives in her boudoir seclusively.
She endeavors to change her fate, and he spared no effort to win every battle. They meet each other every day, well, it’s night to be accurate. Is that a dream or not? She pleads to marry the seignior to win peace for her family, only to find he is the one she is going to marry.
“Growing old with you under the same roof is my long-cherished wish”, thought them both.

- Description from Novelupdates

This legend tells the tale of the protagonist, Kuroki summoned to protect the demon king from the hero.

Kuroki, unbeknownst to him, suddenly came to another world. He was summoned by the demon king, Modes. The territory which the demon king overrules was in the midst of being destroyed because of the hero. He had no choice but to bow before Kuroki.

“Please save us, Savior Dono!”

Kuroki nodded, deciding to save the demon king due to an unexpected turn of event.