A manga where strong hero goes to hell, angels are the villains

The hero who is a mere mortal comes down to hell (not really sure if it had a special name) cause the earth was too corrupted by the angels.
The demons, especially a girl who is in the top ranks sided him as their friend and fight against waves of angels.

Eventually the hero’s brother was found to be a villain. The hero pair go up to Earth the fight him and learn about some horrible truth of how poison was spread throughout using snow to kill normal people.

And I don’t really remember any other clues except some big thing which stored the memories of the ancestors(?) which got deleted towards the end of the story.

It’s a completed manga with chapters less than 300