First,
they are not referred to a man. They were unseen and they were describes as unclean, wicked spirits. They may have have spirit and name like Legion but the description does not match human kind.
Matthew 12:43 When the unclean
spirit is gone out of a man, he walketh through dry places, seeking rest, and findeth none.
Matthew 12:45 Then goeth he, and taketh with himself seven other
spirits more wicked than himself, and they enter in and dwell there: and the last state of that man is worse than the first. Even so shall it be also unto this wicked generation.
Second,
they are not referred to the Devil and his fallen angels. This of course do not have reference to Satan and his companions at the time they were cast out of heaven because of their rebellion. For there is only one Devil, the Old Serpent, the dragon.
Revelation 12:9 And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him.
So who are these malignant creature?
these malignant creatures were still to be categorized as
angels although, they were not part of Satans Rebellion. In the New Testament, these were referred to 2 Peter 2:4 and in Jude 6. Angels are ministreing spirits and were messengers of God, however, these were the same angels that sinned, which kept not their first estate. The most probable sinned of these angels would be their intrusion with the daughters of men. In Genesis 6:2 said "That the sons of God saw the daughters of men that they were fair; and they took them wives of all which they chose.." We have to note that term "sons of God" in the Bible may not only refer to Adam and to the believers (John 1:12) but also the angels. Accordingly, those angels acted in whoredom produced wicked giants (Gen 6:4-6). The context of Leviticus and in the book of Deutoronomy solidify that it has to do with the SEX sinned or PERVERTIONED. We also note that angels were referred to as SEXless, however as we have said they kept not their first estate and they did sinned.
.
2 Peter 2:4 For if God spared not the
angels that sinned, but cast them down to hell, and delivered them into chains of darkness, to be reserved unto judgment;
Jude 1:6 And the
angels which kept not their first estate, but left their own habitation, he hath reserved in everlasting chains under darkness unto the judgment of the great day.
Leviticus 17:7 And they shall no more offer their sacrifices unto
devils, after whom they have gone a
whoring. This shall be a statute for ever unto them throughout their generations
Deuteronomy 32:5 They have
corrupted themselves, their spot is not the spot of his children: they are a
perverse and crooked generation.
Deuteronomy 32:17 They sacrificed unto
devils, not to God; to gods whom they knew not, to new gods that came newly up, whom your fathers feared not
When they were created? I do not know when but certainly they were created. I hope this will not lead me to the Gap Interpretation hehehe..
Thier Original purpose? They are God's messenger and their relationship to mankind is to minister to us by way of protection.