MC With a world inside him

fatkut

Dear Readers;
Anyone knows of a story of an MC with a world of inside him. I remember one but it contained too much Harem that it irritated after some time; the MC was literally had to fuck women to upgrade his worlds level. Beside of this one; do you have any recommendation ? 

Thank

BoosBerria

I think Stellar Transformations is like that? Been a long time since I read it though, so can't remember properly. And I don't think there was too much harem (but again, don't remember properly)