There's definitely something wrong with this murder mystery game - Chapter 818 - 689: The Decline of the Mystery

He died in his first life, as an ordinary human inside an ordinary planet.

In his second life, he swore to live a life of supreme power, and so he did. He reached the apex and exterminated his enemies to oblivion.

Dying, he was reincarnated in a world which could use Chakra. He became The Overlord Of Every Being, Ruler Of 6 Universe.

Unfortunately, he died. Using a mysterious method, he was reincarnated once again inside the world of Tales of Demons and Gods.

Li Yubing and Tang Xue were deskmates throughout the whole six years of primary school. After being plagued by Tang Xue for the entirety of this period, Li Yubing saw his chance and broke free with his secondary school selection. With no contact for yet another six years, who knew that Tang Xue and Li Yubing would one day meet again in university…

- 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.

Genius, antisocial, solitary, intractable , maniacal.

At the turn of every era, it is he who raises the flag of the rebel cross.

Winners take it all, losers take the fall.

He who brings order to a chaotic world, assembles talents and masterminds.

He who hides among the crowd, yet stands on the top of the world.

— The one and only, him.

- Description from Novelupdates