I Have the Alchemy Emperor in My Head - Chapter 199 - The Match Against Ultimate Speed

1. Download a suspicious game
2. Catch a few magical pets as partners
3. Go through interesting daily routines and lead the pet shop to a whole new level

“My daughter will kill me.”A poor man, exhausted and overwhelmed by debt, dies and finds himself in his favorite novel as Arzoth Draven—the character he despised the most. Arzoth Draven is the infamous prince who constantly tries to undermine his brother, Evren Draven, the story's main protagonist. He abandoned his illegitimate daughter in a basement, only to be killed by her years later. Now, having transmigrated into the role of Arzoth Draven, can he avoid this grim fate? And on top of that, he also possesses a system.

I exist in the darkness, disappear under the bright light, and will eventually devour the sun and turn into the shadow of all things… Known by people as the indescribable terror of darkness; the king of shadows; the dark day; the existence of the shadow of the world , is still just a somewhat special high school student, facing a weird death game…

- Description from novelbuddy

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.