Talking about 50 kinds of meditation evil spirits. Is the evil spirit a demon, or is it really disturbed by all beings in the magic way?

There are demons. However, it is also clearly recorded in the Shurangama Sutra that there are demons and grandchildren. The following is a passage from the Shurangama Sutra:

..... You are also wasting your time. You can't get out of the dust without lust. No matter how clever a person is, if he continues to commit adultery, he will also fall into the path of the devil. Top demon, middle demon, low witch. These demons also have disciples, and everyone claims to be supreme. After my death, in the last law, many demons flourished in the world. ……