I imagine it as a dystopian assembly (I know that was redundant).
They hide away in stadiums so they can control the living and avoid exposure to diseases caused by corpses. It takes the birds 50 years to eat the corpses, so they are living dorm-style in grey concrete stadiums with no privacy, fresh air, etc.
The bros go around gathering preserved food and bottled with masks so they don't catch disease. And that is what they all eat.
The toilets won't flush and there is no heat or air conditioning because electricity and water treatment plants stop running. Combined with the fact that fresh air is limited indoors, and they run out of deodorant after the first few years, it completely stinks. Soon the stank and sewage create dissidents and a splinter group leaves the stadium under prohibition from the elders. Satan kills them after the 1000 year imprisonment because of disobedience, while the obedient all die, overpowered by each others' body odor and disease.