Infinite System Inheritor Return From The Abyss - Chapter 425 - 423: Upcoming event

Ten years ago, mana descended upon Earth in the form of Gates that opened into other worlds. These Gates contained Magical Beasts of unfathomable strength and power that preyed upon humans and sought the destruction of everything around them.But along with the Gates, humans gained the power of Gifts—super abilities that allowed them to fight back against the monsters and take back their world.Now, the Superhumans with Gifts are tasked with defending the people and ensuring that the Gates, which open all over the world, do not bring about the end of them all....Jason Marc was just your regular seventeen-year-old high school student whose father abandoned him ten years ago. He worked two part-time jobs while also helping his mom with her diner to aid with the finances, but he could have never guessed that his entire world would change on the eve of his eighteenth birthday.Now, with more power than any one man should possess and an army at his beck and call, Jason works toward protecting those close to him while finding out the truth behind the emergence of the Gates—and preventing the end of the world.

The doomsday fell upon the earth when a dragon coffin sealed under a snow mountain for ages shifted, and the civilization of gods and devils began. The whole universe turned into a fantastic new world where everyone could rise to the top through cultivation. A lucky young boy seized the opportunity, and started his journey to be an overlord in cultivation.

- Description from Novelupdates

The older young Lisko woke up and found that he had become an American. He took over his father’s ranch and began to live in the United States.

- Description from novelbuddy

Failing in his job hunting, Sanada Kyouichirou was hopeless in this society. When kyouichirou had thrown himself towards the bottom of a cliff. When he woke up his body had returned towards when he was in fifth grade of elementary school. He did not want to have any regrets in this life so he had decided on building up an harem in this second life.

The elder sister that he admired, a senior and president of the student council at a school for rich young girls, a strong minded upper classman at school. The poison fang of Kyouichirou who had pretended to be a innocent child attacks those girls.