MTL - Uncle is Up - Chapter 23 never well

When the Terminally Ill Noble Allenbert woke up from his fever, he realized that he was the reincarnation of Karzan, the mad dog who roamed the underworld.…But something about this place doesn’t feel right.“Allenbert, nobles need secrets and darkness.”The sinister and chilling schemes of his brother, like a snake, are suffocating him from all sides.“You’ve been causing quite a stir lately.”The powerful and authoritative eyes and ears of the head of the family are hidden everywhere, watching him.“…When will I see Mother?”Meeting his mother, who has secluded herself due to a mental illness, seems impossible.“But it’s okay.”Karzan failed, but Allenbert’s journey is just beginning.“Two lives, two revenges.”There’s no mercy.I’ll pay back with interest, and make sure it’s done properly.

A teenager named Evan Mason was reincarnated into the magical world of Harry Potter and goes to school at Hogwarts!
With only his knowledge of the future and great talent for magic, he takes the path towards the top of the magic world, only to realize that ever step he took, changed everything!

- Description from Novelupdates

After transmigrating to Hong Huang and becoming a minor shaman in Hou Tu’s tribe, Chu Xuan shocked everyone by repeatedly offering poisonous plans in order to avoid becoming Cannon Fodder in the Great Calamity.Who would have thought? The poisonous plans were incredibly effective.The Demon Clan established the Heavenly Court and united countless races?Chu Xuan: Establish the path of the Heavenly Tribulation and share the power with the Heavenly Court. From now on, all beings must undergo the tribulation!In Zixiao Palace, it was said that those without Primordial Spirits couldn’t listen to the Dao?Chu Xuan: Create the path of the Heavenly Demon as a tribulation for Primordial Spirits. All who possess one will suffer!During the war between the Wu race and Demons, countless souls were left with no place to go, and the Calamity Qi of heaven and earth ran rampant. Who asked Hou Tu to reincarnate?Chu Xuan: If you don’t work hard in your cultivation, you’ll end up as brothers in the Ten Thousand Souls Banner.…Chu Xuan: I have a plan that can completely resolve the Great Calamity of the Demons and Wu races!Hou Tu: Chu Xuan, calm down first. Things haven’t come to that point yet.

The world was once at war with 10 alternate worlds. This was known as the Concept War and our world won 60 years ago. All of this was concealed so no normal people are aware of this fact in the current time.

After the death of his grandfather, the high-school student Sayama Mikoto is suddenly summoned by the giant corporation IAI. He learns this world is headed for destruction due to the acceleration of the Minus Concepts. To prevent this, negotiations must be undertaken with the survivors of the other parallel worlds so their 10 concepts can be released.

And so Sayama is caught up in the final battle to clean up after the Concept War which left behind so much enmity.