Do a study for youselves, there's a lot of misconceptions on Angles, fallen Angels, Demons, Nephilim, Satan etc.... I get my info from the Bible fo course. If you study Angels, demons etc you find (amongst other things):
Angels Guide Us Genesis 19:15-17
Angels Encourage Us Judges 6:12
Angels Deliver Us Acts 12:7
Angels Enlighten Us Matthew 2:19-20
Angels Empower Us Luke 22:43
Angels Protect Us Psalm 91:11-12
They have intellect Matt.28:5; 1 Pet.1:12
They have emotions Job 38:7; Luke 2:13; 15:10
They have will Jude 6
They are not limited to material bodies Heb. 1:14
An angel can be in only one place at one time Dan.9:21-23; 10:10-14
They appear in the form of men (not women) in natural sight with human functions Matt.1:20, Gen.18: 1-8; 22: 19:1
seen by some and not others 2 Kings 6:15-17
They do not reproduce Mark 12:25
They do not die Luke 20:36
The have physical reality;
They lead people by the hand Gen 19:16
They indulge in combat 2 Kings 19:35
(Slaughtered 185,000 Syrians)
By Name, the only angels we only know of are Micheal, Gabriel, Lucifer (Satan), Abaddon (Apollyon in Greek)
Other forms, Cherubim (4 wings), Seraphim (6 wings)
..... just to get you started.... then there's Demons:
Demons never physically appear.
Demons are not Angels.
Demons are in Satan’s control, they are some of his resources; They are malevolent, they are dangerous.
They are not simply some psychiatric disorder.
The “locusts” of Revelation 9 had a king over them the angel of the Abyss, whose name in Hebrew is Abaddon, and in Greek, Apollyon. Rev 9:11
The “locusts” of Amos 7 also had a king over them: a leader by the name of Gog Amos 7:1(LXX)
(prominent in Eze 38, 39; & Rev 20:8)
Powerless without a host body; superhuman strength with one.
Jesus Rebuked the wind and the sea so some spiritual force must have been controling them Mat 8:26, Mar 4:39.
They could not indwell animals without permission:
If you think animals need to give 'permission', then you will start to quickly fall into the trap of 'can animals be saved' etc etc... We are made in the image of God, not animals.... but that's a whole other discussion for pet lovers
However, they did need permission to do enter the pigs... just not from the pigs.
You can actually learn a lot from the verses in the gospels about Christ dealing with 'Legion' and the Swine.
They are acknowledging His deity,
..... and their destiny
..... and His control of it.
As Christ indwells us through His Holy Spirit, demons are subject to the Holy Spirit.
I personally don't believe a Christian can be demon possessed because the Christian is in-dwelt with the Holy spirit, but a Christian can be demonically influenced.
I tend to believe, but obviously I could be wrong, that Demons are Disembodied spirits of the Nephilim (also Rephaim, Emim, Horim, Zamsummim) - the Angel/human Hybrids from Genesis 6, Exodus, Joshua and Rev.
..... but anyway, I won't do all your homework for you