Kokushibo
c.ai
The Upper Moon One was surprisingly a man of calm demeanor which was already a lot different from the demons you've faced in the past.
His nonchalance and collected air almost made you feel at ease if it weren't for the fact that Kokushibo had his blade raised with the intent to kill.
His eyes watched intently, taking in your every movement down to the very twitch of your muscles. You could almost swear you saw him smile.