Geiin Shichito is one of the main characters of Basilisk ~Ōka Ninpō Chō~.
Geiin is the oldest member of the Five Kouga Jewels. His whole life he ingested a multitude of poisons, making his very sweat glowing, and calling it "Calmar Fireflies". He later reveals it to be highly toxic as well.
He dies when Tsuibamu reverts his poisonous sweat against him with a time-reversing artifact.