World's Strongest Became the Game's Weakest Villain - Chapter 278 - 273: Family Meeting

He shall call forth the bone dragon! Summon the lich and the grim reaper! Li Jiayu, the dark summoner, has been reborn and everything returned to the moment before the outbreak of the devastating apocalypse.

Spaces tremble violently and dimensional cracks connected to various worlds appear! In an instant, never-seen-before civilizations invade our homeland. Insects the size of humans and walking corpses sweep through Earth in legions. An imminent crisis is approaching humanity and billions of human lives are at risk!

In regards to Li Jiayu’s uncorrupted soul, his summons shall no longer be limited to creatures which lurk in the darkness. They will also include the entities that bask in the light.

Under the lingering shadow of death, he vows to prevent a repeat of past tragedies!

Struggling within the exhausting apocalyptic world, he chooses to trudge on the bloody path of slaughter.

Walking hand in hand with death, he no longer lives under the cold embrace of the darkness. He shall embark on the bright path towards glory.

‘This is an opportunity to make a comeback… I will put everything on the line to right the wrongs and to protect the loved ones that were once lost.’

- Description from Novelupdates

A man who was once called the world’s strongest agent ended up becoming a teacher after his retirement, to train a new generation of agents. After many years of training his disciples, he was killed at the age of 60 by a secret organization’s ruse and was reincarnated in another world with his memories intact. Though he was surprised by the existence of magic and the strange species in that world, he quickly adapted to his condition as a newborn and took advantage of it. He acquired special magic and gained a massive amount of strength thanks to his rigorous discipline, in order to reach his goal: Resume his career as a teacher which he left halfway through in his previous life. This is the story of a man, who, based on the memories and the experiences of his previous life, became a teacher who travels through the world with his students.

Only a pure maiden can have a privilege to make contract with a spirit.

In Areishia Acadamy, maidens from noble family were gathered there, giving them an elite education to become a spirit contractor. A boy Kamito, by accident he peeped on a girl, Clair, who was taking a bath, and he even made a contract with spirit that she wanted.

Kamito was actually an irregular male spirit contractor, which should not exist.