Hitotsuki

Hitotsuki (一鬼) is an oni who once fought alongside Tora, and various other youkai, to take out Hakumen no Mono. He has immense strength with the ability to swallow and digest an entire person in an instant. He is considerably stubborn and tenacious and is unfriendly with Tora, even though they joined forces 800 years ago together as fellow soldiers. Hitotsuki makes a bet with Tora when they confront each other in the present which results in his loss.