There was none. What I said in my article is the first chapter. He was summoned in the middle of a subjugation and he one punched the monster before disappearing and reappearing back on earth where he previously was.
I put in -ish because I'm not entirely sure it could be tagged as Isekai since the MC gets repeatedly summoned and then goes back to earth.
This was a series I read a couple of years ago about an overpowered MC who gets repeatedly summoned to another world to defeat a demon king or something of...