Hidan's Chakra Element
Okay here's the deal! Though his elemental chakra nature is unspecified ....since he uses a spiritual jutsu we can say that his chakra nature or more specifically his jutsu nature is "yin release" ..... (Like that of shadow bind of nara clan)
Update: It is not only yin but also "yang release" cause he share his physical damage too ... so it might be a "Yin-Yang release"