Bishamon was born in 1673.
Bishamon is possessed by demonic armor named Hannya and demonic sword named Kien.
Hannya, The Cursed Armor
The armor is actually a Makai demon. It shines if soaked in blood.
Kien, The Blood Thirsty Sword
The sword, Kien, only gets sharper with the more people it sliced through.
In the UDON comic series, he fought Donovan the Darkstalker Hunter.