I know that when you hear principalities powers you are used to imagining horrible monster spirit creatures that always stop prayers you can be right but among principalities and powers are not only evil spirits because even the Bible tells us that Christ is the head of principalities and powers (Colossians 2:10)that means among all those spirits they are good spirit that are in the rank of principalities and powers and there are bad spirits so if Christ is the head of all principals then with his blood you can have sure Victory. But not like saying I bind every principalities and powers..... Let's pray with understanding