The answer
We do not believe this at all. It is not supported by any creed or historical evidence. We do not know of any person descending from the devils. It is something unreasonable and can be refuted on basis of faith. Among the refutations we mention the following:
The devils are spirits having no bodies to procreate like human beings.
Devils are spirits because they are angels and they are called spirits in the Holy Bible (Luke 10:17,20).
They are even called "unclean spirits" (Matt 10:1) and "evil spirits" (Luke 7:21; Ac 19:12). How then can spirits procreate? And how, without having bodies, can they produce an offspring having bodies?
Of course sexual relations and marriage have no existence among these spirits.
The devils, though they lost their holiness, still have the angelical nature. That is why it is written in the Revelation that a war broke out in heaven between Michael and his angels and the dragon and his angels. They fought, "So the great dragon was cast out, that serpent of old, called the Devil and Satan, who deceives the whole world, he was cast to the earth and his angels were cast out with him." (Rev 12:7-9).
And whereas they are angels, see what the Lord Christ said about the angels when speaking about the Resurrection. He said, "For in the resurrection they neither marry nor are given in marriage, but are like angels of God in heaven." (Matt 22:30).
Angels do not marry and this applies to the devils as they are angels. The devils may arouse sexual feelings in human beings but they themselves do not have such sexual nature. The devil may appear in the form of a man or a woman, however:
There are no males nor females among the devils. They do not have bodies of men or women, nor do they have ovum or sperms. They cannot give a human offspring nor even a devil offspring. The devils are great in number because of the great number of the fallen angels not because of procreation among themselves. If they do not procreate among themselves, how can they procreate from human beings!
Moreover, procreation needs conformity of kind or species.
For example, no procreation can take place between a fish and a bird, a bird and an animal, nor between an animal and a fish nor between a human being and a bird. There must be conformity in sex and kind. Accordingly, no procreation can take place between a human being and a devil. Besides, a devil has no body.
History has not presented to us even one example of such procreation.
We have not heard of any person born of parents; one of them a human being and the other a devil, so that such a person might give us an answer to the confusing question: Which of the two natures prevails in such a relation, so that the offspring might be either a human being or a devil,
or even a human-devil! Would such a being be visible or not!
Perhaps such questions are due to the stories of demons told to children and regretfully fill the children's libraries. Add to this the stories spreading among the common people and villagers who circulate these stories forming of them an important part of their folklore.
Thrice-Blessed Pope Shenouda III of Blessed Memory