Start By Becoming A Mangaka - Chapter 1182: War Within The School

In a world fractured by conflict and haunted by shadows of the past, Kokushibo—the first Upper Moon demon—meets his end, only to awaken in a new life. Reincarnated as Crimson, a child born into a different family, he carries the memories of a past he cannot escape. Burdened by centuries of guilt yet indifferent to the present, he resigns himself to duty—until an unexpected bond with his newfound family begins to thaw his hardened heart. As he struggles between the weight of his past and the weight of the new life, Crimson must decide whether he will remain shackled to his former sins or embrace the possibility of peace.

This crossing is so strange, death crossing, game crossing, etc. are probably barely acceptable, but why can you cross even if the fish tank is broken?

and actually passed through the magic tree in “OVERLORD” that is said to be able to destroy the world?

No! It is sad enough to regenerate into a plant. The protagonist, Ainz Ur Gong, the undead king, has also accepted the adventurer’s guild mission and wants to kill me!

I want to change my destiny! Live! I want to-surrender!

Ainz: Since he has accepted the job commission from the Adventurer’s Guild, deliberate failure is detrimental to the prestige of Ainz Ul Christine (the “surrender” button has been deducted)

actually died as soon as he crossed, but there is still a chance to return~ from the beginning of the magic tree to this world.

I must change my destiny this time! Live!

- Description from novelbuddy