The Power Of A Shadow Monarch! ; Multiversal Journey [CW: OPM]

Huh? I fought a whole army, defeated the monarchs who were even more stronger than before...

What do you mean I can't go back to my world!?

...I see. So, my existence will destroy the world you say? Fine, let me just choose a successor and then I will go in slumber, I am tired of this already. I spent 90 years for f**ks sake. And this is the treatment I get...

THIS GUY, I CHOOSE THIS KID. He seems to have great endurance like I had when I was younger, the determination to survive as well.

Though the world treated him harshly. It isn't his fault.
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Meet Ether, the successor of the strongest Shadow Monarch, and see him, going though multiple worlds, trying to enjoy his life but getting dragged in the story lines, though he likes it.
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This is my first fan fiction novel, so if there are mistakes do point it out, and yeah, I will be giving it proper updates. Though do check out my original novel as well. Anyways, the current world is:
1. One Punch Man!
2. ???
Do drop powerstones. Thank you.