MTL - Descent of the Phoenix - v2 Chapter 1746 Mysterious come 1

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.

I have a childhood friend.

When the cosmic tyrant Frieza detonated Planet Vegeta, home of the Saiyan race, a twist of fate sent a lone infant—placed in an escape pod by his mother—hurtling through the void toward an unknown destiny. The pod's trajectory led him to a desolate world: Titan, a planet ravaged by catastrophe and long stripped of life.Beneath the shadowed skies of this barren realm, the watchful eyes of Thanos, the self-appointed director of the universe's population balance, beheld an unexpected sight—a child, the sole survivor of Titan’s forgotten civilization... a child with a tail swaying behind him.“A survivor of Titan... From this day forth, you shall be my son.”

When Li Shen’s second personality acts out, her consciousness is sent to a strange place called Split Zone No.13. She is then informed that she can only return home after unraveling the truth.