If your brother’s Priest agrees to get involved but isn’t experienced in spiritual warfare, it could make matters better for a short time but then much worse. Sometimes a priest/pastor will come out to pray with you in your home thinking that it will “make you feel better” or to mechanically perform a standard ritual prescribed in their doctrine. I want you to understand that simply getting a man of the cloth involved won’t solve the problem.
You must get someone who is experienced in such matters and who will prepare your brother for spiritual warfare. Entering into spiritual warfare unprepared can be worse than simply doing nothing because you are engaging the enemy on his terms. You (or your brother) must be very careful, FRiend.
Wise spiritual warfare is more or less the only kind to engage in.