The thing on the yokai medal. I named him "oogama" which means "war scythe" in japanese.

Here is some info about oogama. Oogama is a very hostile yokai. He's often associated with the grim reaper as his victims he inspirits are usually found on the ground with a bleeding wrist, but not dead. Oogama had had a few kills before, making him dangerous, but not to humans or yokai. some who had heard of him refer to him as "the angel who wields a scythe" or "the scythe wielding ghost in a cloak". He may be harsh, but he has a soft side that some yokai could reach, but not many could see it. Insomni is one of the yokai that could find his soft side, she gets along well with oogama, and is mostly found wandering around with him at night.