From Nun to Real Heiress: Expert at Turning the Tables - Chapter 1549

A good-for-nothing man married a beautiful girl but was kicked off the bed on the wedding night. Furiously, he wrote a bill of divorce and ran away.
He was schemed a car accident in which he nearly lost his life. However, it turned out to be a blessing. He swallowed the soul that passed through the outer world, thus obtained superb medical skills and martial arts.
Later on, with the silver needles and invincible martial arts, he embarked on the road of counterattacks and was committed to his great dreams.

- Description from Novelupdates

Lyle Walt is a young noble boy and heir looking forward to the day he can inherit his family’s territory. Except around when he was 10 year old, his parents started neglecting him more and more in favour of his little sister, Celes.
On his fifteenth birthday, he is challenged to a duel by his sister to see who will inherit the household and horribly loses, being cast out of his family. Afterwards, he gets treated by the family groundskeepers and receives the family heirloom Gem from him that Lyle’s grandfather had entrusted to him. From there, he begins an aimless journey with his childhood friend and former fiancée, Novem, and the Gem-turned-Jewel that houses the memories, personalities, and Skills of seven of his ancestors.

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.

Sherlock is a new generation Dungeon Lord whose ambition is to become the greatest Devil King and building up the greatest Dungeon in the Underworld.

He summons a group of other-worldly goblins who give themselves strange names, form cliques, engage in commerce, and even fight among themselves.

They call themselves—Gamers!

- Description from Novelupdates