Absolute Depravity: Reincarnated with a lustful System - Chapter 81 - Prayers To Summon A Demon

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

The empire has turned into the land of the undead due to a spell gone wrong. God summoned heroes from countless worlds to purify the empire and plant new hope. Lee Shin Woo, an ordinary earthling, was also summoned. As an undead, that is.

Ning Yechen used to be the Demon Lord. He singlehandedly took over the Demon Realm and attacked the Heavenly Realm. His name preceded him throughout the Six Realms. He got tired of fighting, so he quietly went into seclusion and became a happy hermit.One night, an Empress from the Heavenly Realm fell into the Mortal Realm after someone drugged her with an aphrodisiac. She inadvertently fell into his room, and they made out. After the deed, the Empress quietly left. Just when he thought he would never see her again, she showed up in front of him ten years later, bringing a child, saying it was his daughter and demanding accountability from him! “She’s your daughter. You have to be responsible for us!” Ning Yechen was stunned!

The Red Dragon came from the vast wild wastes, coveting all the strength in the world. It once had countless titles: Mountain's Wrathful Flame, Infernal Calamity, Crimson Emperor, Ashen Dragon......The world trembled under the shadow of the giant dragons. He stirred up the craze of the magic industrial revolution; in the empire he established, Wyverns roared, artillery fired in unison, and steel beasts appeared in the sky and on the land, while disasters from another world rampaged everywhere.“Submit, or die.”Cassius spread his wings, blotting out the sun, and gazed down at the trembling humans, elves, and dwarves below, saying thus.......It is a story about a Red Dragon with a player template conquering, ruling, and transforming an alternate world.(Pseudo of DnD, The Fourth Calamity, Red Dragon)