I heard Bleach the Movie: Hell Verse is not canon so all of the Hell scenes can't be taken seriously, but the whole concept of the Hell is actually canon (chapter 12, page 9-13 or anime episode 5). If that's so, how does Hell fit into the whole Bleach universe? Or maybe the better question is what is Hueco Mundo?
If Soul Society is supposed to be the Heaven, and the opposite of that is the Hell, does that make Hueco Mundo the purgatory? Logically that would be the best explanation, but Hueco Mundo is the land of hollows and it's known that hollows lose their self awareness. So the question is how can one be purged if he lost his self awareness? Only way to gain that self awareness back is to kill other hollows and to become Menos Grande, then continue killing to become Adjuchas and later on to become Vasto Lordes. I find it a bit disturbing that the only way for one to be purged is to kill others.
One more thing caught my eye. If sinners go to Hell, and they can't escape from there because they are bound by unbreakable chains, why those chains don't exist in Hueco Mundo? Why are those hollows allowed to freely enter the World of the living and start rampage on the innocent human souls? They have a lot of freedom for creatures that exist only to kill and devour other souls. I think Kubo should better explain the whole concept of hollows, why do they exist and why is so important for soul reapers to keep the balance between the Hollows and the Wholes.