I saw this “Hells” and “omens” in some PDF I got, what is they?
Sounds like something based off Divine Comedy/dantes inferno, other than that no clue. This is about the only reference you will find regarding 7 hells.
With that said there are various cultures that have a view of the underworld that has various levels but this is not the monotheistic hell where the big scare man in the clouds locks you away to suffer for all time.
In most culture the underworld is a place of rest and reflection and sometimes pain as a result of what you percive within yourself.