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!fantasy@lemmy.ml
use this browser to find more - https://lemmyverse.net/
I think literature.cafe has the only activeish book communities really.
Most people sub to all the related communities, so if you post here (and the series specific ones) there are normally responses.
There is no one pushing these communities currently until Fax (one of the sffa admins) gets some more time to spend here.
Thank you for your comment!