MTL - Mage Network - Chapter 55 :world Tree? Who are you?

The Grand Sovereign, Kang Chul-In. The man who was so strong that he had to be defeated. Having lost, he must now go back in time to take up the challenge of becoming supreme in the Continent of Pangaea. Will Kang Chul-In be able to overcome the 9 other Grand Sovereigns in order to grasp the Continent of Pangaea within his hands?

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

This is a story about the protagonist getting the system, going crazy in the biochemical apocalypse, producing aircraft and tanks, destroying zombies, saving good people and killing bad people.

- Description from novelbuddy

[Earthlings! You have been summoned to participate in the Universe's Armageddon...][The first batch of beta testers are now being issued!][A total of 10 million spots have been issued!][You have been selected!]“What the F***” Arthur, a teenager in the slums shouted as he heard the global announcement.[Talent Awakening!][System...Error!][SSS Talent: Primordial Summoner]I was meant to summon a powerful primordial beast that would carry me all the way.So... why?“I SUMMONED A CAT!” He shouted, looking at the cute cat in front of him.By the time the game had merged with reality, Arthur already has dozens of legendary summons to aid him against the forces of evil.[You have summoned the SSS-Level “Primordial Dragon”!][You have extracted the SSS-Level Skill “Berserk”!]