This is book 3 of the series!
If you are looking for book 1 or 2, they are located here.
https://www.royalroad.com/fiction/34776/new-game-reborn-as-a-reluctant-demon-lord-book
https://www.royalroad.com/fiction/46513/restart-reborn-as-a-reluctant-demon-lord-book
Spoilers for those books below.
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It was a time loop. The magic I had strived for centuries to create was the very thing that got me into this mess in the first place.
Broken, I turned my blame to the one thing that I could truly claim as responsible for my situation.
The OmniverseEngine itself.
I swore that I would take it down by any means necessary, but to do that I would need some unconventional, and unwitting, allies on my side. After all, not even demons want to destroy all of existence.
This is the final tale of my life in Placeholder. The tale of my last descent into my role as [Demon Lord] as I threatened all of the OmniverseEngine... And the tale of what I found after finally hitting the bottom.