There's defs something purgatorily about the host cold storage. It mirrors that the host have a dreamless sleep, which would be torture to the human mind. yet the hosts can keep long memories and its in their programming they can overcome them being wiped out. I think the hosts are more representative of angels, due to their supernatural nature.

I think the non-sentience of the hosts is an Underworld theme. Its not like hell as they forget their torture for the most part, and not everyday bad things happen; its very human as their torture doesnt really span a life narrative but a closed time narrative of a day to months. The cyclic nature of their existence is interesting in the big picture too.