I Dragged My Fiance's Uncle off the Altar - Chapter 6

Kaito Nakamura, a shy university nerd, thought he’d found love when the stunning Aiko chose him as her boyfriend. Their sweet, fluffy romance fills his lonely world with hope—until he discovers she’s cheating on him with multiple guys, reveling in the taboo thrill of betraying someone so innocent. Heartbroken and humiliated as explicit photos of her circulate online, Kaito’s tears are interrupted by a mysterious popup: the “Revenge NTR System Beta.” Promising retribution but with a chilling condition — he can’t break up with her.Contains Ntr, read at your own risk

Solver Keter, one of the Five Lunatics of Lawless City, regresses to when he was the illegitimate son of a doomed archery family.“If I regressed and couldn’t even save my family, I might as well go kill myself.”For my family? No, for my freedom!

Chu Yang, the Ninth Master of the Nine Tribulations Sword, sacrificed almost everything he had for the sake of improving his martial arts, including the love of his life. After spending three years locating the fifth fragment of the Nine Tribulations Sword, he was ambushed by all sides at that very place. Mortally injured with no means of escape, Chu Yang executed a sacrificial technique by plunging the Nine Tribulations Sword into his very own heart. “With the blood of my heart, ten thousand tribulations will collapse!”

After witnessing the death of all his ambushers, Chu Yang’s vision began to darken. At a distance, moments before his death, he saw the mastermind who had plotted his downfall — Mo Tian Ji. With that, his eyes finally closed.

However, with a start, Chu Yang once again awoke to find that he had returned to when he was sixteen years of age! Furthermore, the Sword Spirit of the Nine Tribulations Sword now resided within his Dantian, the energy center of his body! From that very moment, Chu Yang would then begin to right all of his past regrets, and carve his very own legend by fulfilling his destiny as the final Master of the Nine Tribulations Sword, and defeating the Heavenly Devils beyond the realm of the Nine Heavens Continent.

- Description from novelupdates

After 2000 years has passed, the ruthless demon lord has just been reincarnated! But his aptitude at an academy for nurturing candidates for demon lords is, “Inept”!?

Having the capability to destroy humans, elementals, and gods, after a long period of countless wars and strife, Arnos the demon lord became sick and tired of all that and longed for a peaceful world, so he decided to reincarnate to the future.

However, what awaited him after his reincarnation is a world too used to peace that his descendants became too weak due to a huge weakening in magical powers.

Arnos enrolled in the Maou Academy established to find any students that might be the demon lord’s reincarnation, but his powers are too extraordinary that those in the academy couldn’t properly judge his powers, so he’s regarded as an “Inept student”. Being underestimated and avoided by most people there, he recruited a girl friendly to him, Misha, as his subordinate and comrade, and strives to climb to the top of the demon race hierarchy to one day reclaim his former title and status.