Blood Angels already do that. They sleep in their Sarcophagi a lot.
The Charnel Guard are a chapter I'd love to see something for. The idea of using stasis chambers to fend off the Blood Angels' issues makes a lot of sense, and also happens to perfectly match the aesthetic of vampires slumbering in their crypts.
I believe they’re usually duplicated as rejuvenate in aspect though rather than stasis locking them to not go crazy for a bit longer? Either way I like the lore it’s not too on the nose as that’s how they ascend to the chapter rather that being a we’re vampires troupe
The concept of stasis to help control the mad ones has been a thing used for death company for a long long time, including Lemartes.
But yeah, they're also used for rejuvenation, and to help ease the red thirst.
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