Ryuu Kusari no Ori -Kokoro no Uchi no “Kokoro”- - Chapter 4[LN] Volume 1: .1

Reborn as the ill-fated Third Kazekage from the original series, I am determined to rebuild Sunagakure into the strongest Hidden Sand Village through tireless effort and visionary leadership. My goal is to survive and thrive in the recurring Shinobi World Wars.I will show these ninja, who are obsessed with slaughter and conspiracy, what true 21st-century wisdom and modern governance look like.The world of ninja is not a story written solely by Konoha.

Transmigrating to the disciples of the Demon Sect, and relying on the skill modifier to become a giant of the Demon Dao.

[Detected the technique “Blood Nerve”, relying on devouring blood to practice]

[Side effects: easily affected by the spirit contained in the blood, becoming bloodthirsty, bloodthirsty, mad, and even brain dead]

[Please wait a moment, the system is being modified…]

[Ding! The modification is complete, and the side effects are cancelled]

- Description from novelbuddy

Kai of the Sorcerer’s Tower is one of the last mages left, barely surviving in a world ruled by creatures of the dark — where the era of mages ended, and most of the lands got contaminated with dead mana. To save his world and fulfil his master’s last wish, he put himself through a forbidden ritual, risking his soul being ripped into pieces to make his way into the past. In an era with abundant mana — an era yet to enter the Golden Era of Magic. Things go wrong, of course, as they always do, and he finds himself thousands of years before the world fell to mana contamination — in the body of a young lord, Arzan. All is not well, though, as the young lord was murdered by someone right at the cusp of a beast wave threatening the territory, while larger threats loom on the horizon. There was a lot to do for Kai to regain his former strength in this time of primitive technology, but then again, he might just be able to change that.

This novel is also known as Master Fu's Mysterious Darling Wife

She is the The Young Miss of Military family Shen, her face is peerless, her temperament is cold, and she is her family’s treasure, but isn’t accepted as one’s child by her mother;

He is The Sole Heir to the top giant Fu Family, his power is unparalleled, indifferent high-born, the captain of the mysterious military force, and the youngest commander-in-chief.

Because of her grandmother’s wishes, she married him at lightning speed. She thought that it was a marriage that she needed, but she didn’t expect to be greeted with his extreme pampering.

- Description from Novelupdates