I don't think Fujin will achieve his goal. Things are heading towards a battle royale and it would be difficult to kill Hidan and steal his body in front of various monsters. It might be possible if Itachi helps discreetly, but it seems difficult, they don't even know each other.
If he uses hiraishin and cut of the hand of itachi, he could use and modify the ring to instead of absorb the chakra of tailed beast, to absorb normal chakra into his body, increasing his chakra, or something like that, good job bt2.