He said himself at one point that he wanted to die. Jashin wouldn't give him what he wants, even if he was a devoted follower. it's been 17 years(i guess) since the the fourth shinobi war came to an end. so hidan's head couldn't have stayed alive underground for 17 years.
"The Judgment" (下された裁き, Kudasareta Sabaki) is episode 78 of the Naruto: Shippūden anime.
Hidan - Blown up by Shikamaru into pieces, and then crushed by debris. Kakuzu - Killed by Kakashi's Lightning Cutter.
Synopsis: Following Kaguya's defeat, the Sage of Six Paths has to return to the afterlife, taking the reanimated heroes of the past with him. To free the world from the Infinite Tsukuyomi's hold, Naruto must combine his tailed beast chakra with Sasuke's Rinnegan and weave the Sign of the Rat.
A: Walnuts don't always come in a perfectly standard size. We found on the California Walnuts website, walnuts.org, that ¼ cup of walnuts is approximately 1 ounce. That amounts to between 12 and 14 halves.