High-level demons collect low-level demons as warriors in attempt to obtain a key containing the blood of Christ. The key is guarded by immortal warriors called Demon Knights.High-level demons collect low-level demons as warriors in attempt to obtain a key containing the blood of Christ. The key is guarded by immortal warriors called Demon Knights.High-level demons collect low-level demons as warriors in attempt to obtain a key containing the blood of Christ. The key is guarded by immortal warriors called Demon Knights.