An Arch Demon was an enemy first encountered in the circle of Violence. They are the third choir of the fallen angels and among the original fallen. They resembled winged versions of the Guardian Demons armed with a pair of swords.
The first objective in killing an Arch Demon was to get them down to the ground. Block their aerial strikes and dodge the ice blasts after they flapped their wings (If you are struck, you would have to repeatedly press circle/B to escape). They would also dive down in an attempt to charge the player which could be blocked or dodged. While it was vulnerable, strike with several quick Scythe attacks and follow up with Cross attacks while in the air. Once prompted, the player had the opportunity to use a grab move, slicing it's wings off. This must be done in order to punish/absolve them. Otherwise, they would normally die after sustaining sufficient damage.