if he had an elemental attack or any other jutsu - he would've easily used it against asuma or shikamaru, when shika was out of chakra, during their final confrontation...ya i agree if he had it he would be sick.
i wonder though did he have any elemental attacks.
simply said: hidan is like a witch doctor or a cult member who possesses good fighting skills...an immortal one - by how? it remained unexplained in the series...the only attack that he has is that curse thing...its either he kills the guy by pounding on him with his scythe, pure taijutsu style - or curse him to death whenever he draws blood...