Here darling! I have lists for each category, I tagged which ones are yaoi and shounen ai to make it easier. I hope you enjoy them!
Dragons ⚜
https://www.mangago.me/home/mangalist/2136760/
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Werewolves
https://www.mangago.me/home/mangalist/2137878/
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Vampires
https://www.mangago.me/home/mangalist/1566980/
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Mermaids
https://www.mangago.me/home/mangalist/1741466/
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Gods / Angels
https://www.mangago.me/home/mangalist/2224959/
Any good bl supernatural recommendations