Keep. If you already brought him up once before, why bother doing it again? Im sorry but it just wastes peoples times bringing up an already concluded candidate more than once.
This is why we need that list I was talking about.
Allaround he makes the most with his resources, and Naruto doesn’t have too high standards to prevent Hidan from qualifying.
I personally say cut, others including one of the first thus presumably weaker had a body count of over 100, the terrorist organization was full of cold blooded killers and frankly an extremely high heinous standard. Hidan in another work would be an easy keep but for Naruto not so much. The only thing in his favor is low tier but as mentioned so was one of the earliest villains with over 100 kills shown in flashback, Hidan may have been a little more personal for killing a somewhat popular character that was a mentor for a secondary hero/character but I don't personally feel that's enough to truly justify it.