I'm just glad it din't end like "A Monster Who Levels Up"
When a story that has good potential at the beginning slowly disappoints me that i can make up a better story in my mind with the story's setting...
I'm fine with a harem as long as the guy/MC is worthy of that harem. If he has real ability, non-generic or respectable personality and good looks...
Crossing to the Future, it’s Not Easy to Be a Man
These two fit that perfectly:
The Girl Who Ate a Death God
Katahane no Riku
if these can't satisfy you, i don't know what will
Separate names with a comma.