My friend's relative was a very dedicated silat practitioner during his younger days. At one point of his training he had to go into spiritual training. Years later he told my friend he encountered many strange and creepy things at night during that time. Things followed him home, even strangers came up to him to challenge him to fight. But his faith in Islam kept him safe and out of any trouble. Also heard stories from a friend who became a born again Christian.
This phenomenon is very similar to a body detoxing when you start to be healthy again. Though I am not religious I concede the universe is amazing