Yakurōdokusen

Yakurodokusen is a drunken sage who helped Sango repair her damaged Hiraikotsu. He dissolved Hiraikotsu into a jug and told Sango to go into a second jug and battle the demons inside, warning her that if she failed to defeat them then Hiraikotsu would be no more. Sango goes into the jug in order to battle the demons, who angrily demand to know why she sacrificed them; Sango quickly realizes that these demons are the same ones whose bones were used to create Hiraikotsu. After a short battle, the demons ultimately decide to rejoin Sango once again as Hiraikotsu; while having repaired Hiraikotsu, Yakurodokusen's potions also made Hiraikotsu a much more powerful, it now had the ability to absorb and disperse poison, making it a very formidable weapon.

Yakurodokusen also gave Miroku an antidote that dulled the pain in his poisoned arm, meaning that he would no longer feel any pain whatsoever, although it did not completely heal him and the miasma was still spreading throughout his body.