in which you used to walk when you conformed to the ways of this world and of the ruler of the power of the air, the spirit who is now at work in the sons of disobedience.
KJV
Wherein in time past ye walked according to the course of this world, according to the prince of the power of the air, the spirit that now worketh in the children of disobedience:
ASV
wherein ye once walked according to the course of this world, according to the prince of the powers of the air, of the spirit that now worketh in the sons of disobedience;