Responses
i would reccomend the warrior returns. its not really what you asked for but its the closest I could think of to your criteria. so the person did get isekaied first but it focuses on what happens when that person now with superhuman powers returns to the normal world with normal people and finds everything gone
heres the link if you wanna read it: https://www.mangago.me/read-manga/hero_has_returned/
Is there anything that's reverse isekai? Instead of being isekai'd into the fantasy shits, they get isekai'd into the modern world