Demon Rascals are simple small demons that attack with fireball attacks from a far distance. One exception is when a Demon Rascal teleports to the top of the Siege Beast. From there its Inferno attack can be quite damaging, and there's no way to stop the fire or knock him down other than to kill the very durable Siege Beast itself. This will not kill the Rascal though; it will teleport away and must be killed before it hops into another Siege Beast and repeats the process.