Fallen angels
Matthew 25:41 Then shall he say also unto them on the left hand, Depart from me, ye cursed, into everlasting fire, prepared for the devil and his angels:
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.
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;
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.
2 Corinthians 11:14 - And no marvel; for Satan himself is transformed into an angel of light.
Ephesians 6:12 - For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high [places].
Genesis 6:2 That the sons of God saw the daughters of men that they were fair; and they took them wives of all which they chose.
Genesis 6:4 There were giants in the earth in those days; and also after that, when the sons of God came in unto the daughters of men, and they bare children to them, the same became mighty men which were of old, men of renown.
Job 1:6 Now there was a day when the sons of God came to present themselves before the Lord, and Satan came also among them.
Job 2:1 Again there was a day when the sons of God came to present themselves before the Lord, and Satan came also among them to present himself before the Lord.
Job 38:7 When the morning stars sang together, and all the sons of God shouted for joy?
Daniel 10:12 Then said he unto me, Fear not, Daniel: for from the first day that thou didst set thine heart to understand, and to chasten thyself before thy God, thy words were heard, and I am come for thy words.
13 But the prince of the kingdom of Persia withstood me one and twenty days: but, lo, Michael, one of the chief princes, came to help me; and I remained there with the kings of Persia.
One called a prince has some authority over Persia (Ephesians 6:12). This prince withstood an angel from God sent to Daniel for 21 days and required the help of The chief prince Michael to prevail. No human prince could do this. The angel of God referred to as a “chief prince” therefore the prince of Persia whom Michael helped to overcome must be a fallen angel.
14 Now I am come to make thee understand what shall befall thy people in the latter days: for yet the vision is for many days.
Angel of God dispatched to Daniel in response to his desire to understand and his prayer to God.
15 And when he had spoken such words unto me, I set my face toward the ground, and I became dumb.
16 And, behold, one like the similitude of the sons of men touched my lips: then I opened my mouth, and spake, and said unto him that stood before me, O my lord, by the vision my sorrows are turned upon me, and I have retained no strength.
17 For how can the servant of this my lord talk with this my lord? for as for me, straightway there remained no strength in me, neither is there breath left in me.
18 Then there came again and touched me one like the appearance of a man, and he strengthened me,
The angel of God had the appearance of a man.
19 And said, O man greatly beloved, fear not: peace be unto thee, be strong, yea, be strong. And when he had spoken unto me, I was strengthened, and said, Let my lord speak; for thou hast strengthened me.
20 Then said he, Knowest thou wherefore I come unto thee? and now will I return to fight with the prince of Persia: and when I am gone forth, lo, the prince of Grecia shall come.
The angel of God returns to do battle with the fallen angel.
Daniel 12:1 And at that time shall Michael stand up, the great prince which standeth for the children of thy people: and there shall be a time of trouble, such as never was since there was a nation even to that same time: and at that time thy people shall be delivered, every one that shall be found written in the book.
Michael an angel of God again referred to as a prince.
Both angels of God and fallen angels are called princes, sons of God.
Evil spirts, unclean spirits, familiar spirits, and devils are never referred to in scripture as fallen angels, or princes.
Fallen angels are never said in scripture to possess a person.
Fallen angels are never said in scripture to possess animals.
Some Fallen angels are in chains some are not, only the ones that “sinned”. Jude 6, 2 Peter 2:4
Some Fallen angels have areas or territories they oversee. Some fallen angels are very powerful, so much so that it took two angels of God to overcome one. Daniel 10:13
The only place fallen angels are cast in scripture is out of heaven, down to earth Revelation 12:9 and to hell in chains of darkness. 2 Peter 2:4. Jesus nor the disciples ever cast a fallen angel out of anyone in scripture.
Gods angels have the ability to appear in human form no scripture says fallen angels have lost that ability. Since they still fight against Gods angels that is proof they have not lost, at least some of the power they once held.
The only thing I can see in scripture that evil spirits and fallen angels have in common is that they answer to satan.