The first thing that Magic tries to do is to stop a person from praying. Sometimes, the brain is affected and the person does not feel like praying, increasing the effect of magic in the process. At other times a person does not feel like reading the Quran, whose recitation would weaken the effect of Magic.
It is very important that a person constantly watches his/her level of eman and the noor in his/her soul. The first thing to accomplish that is the five prayers. Amals to break Black Magic hardly work on someone who does not pray. Secondly, if a person who is well does not pray, he/she leaves a door open for any kind of attack to hit then without any protection whatsoever.
Magic does not affect everyone equally. Lets say that the same kind of magic is done on two people. One who does not pray and the other prays 5 times every day, reads the Quran daily and does zikr of Allah daily. While the first person will be destroyed, only a small percentage of the magic would affect the second person.
Same is true while wanting to get cured. If a person is in the habit of praying 5 times daily and reads the Quran and does zikr, he will get cured very quickly. A person who does not pray will take forever to get cured.
The five daily prayers are important for success in worldly life, the afterlife and for fighting against Black Magic. There is no success without the five daily prayers.