I'm starting to wonder if putting their culture (Greek, roman, Chinese etc.) is necessary

Not everyone has studied mythology as much as you have. Greek deities can pretty easily be confused with Roman or sometimes middle eastern ones.

I like to believe that I have studied Greek mythology as well. But I probably haven’t studied as much as reaper has lol.

You think i study 'em hard? I have a friend who's like me, But calls herself "the god of gods", Take a guess why xD

Yep
I still wonder how tho, I mean, It's not like their names match, their regions, or language have the slightest similarities xD
It's like confusing Jelly with Ketchup!

Webtoon has lied to me

It's webtoon, I'd be surprised if something in there was true xD

Jungle juice is pretty accurate

Fair enough xD