There are all in the category of flesh. Celestial beings have bodies. Let’s briefly take a look at a few words here.
Celestial; meaning existing in heaven.
Terrestrial; meaning earthly or earthy.
Celestial beings have bodies. So a Celestial being can’t enter into a human, or an animal because they have a body. The reality of beings outside of this planet exist, and many come and go from this planet. Heb 12:9 Says God is the Father of all spirits.
The Greek word devil in the New Testament is the word Daemon in the Hebrew where we get the word demon from. Daemon is defined as a disembodied spirit. Or a spirit that once had a body. Mostly used speaking of malignant beings in the satanic kingdom. But the body though weak, and dishonorable is what God gave authority to in Gen 1:26.
So once any-body heavenly or earthly is destroyed, the spirit though eternal, ceases from having any authority to operate in this realm. A spirit can walk through a wall but can’t build a wall, its superior is speed and travel but inferior in power in this earth. The only way God could come to redeem mankind was through the womb of a woman. The womb is the gateway into this world.
Any spirit, any alien, any angel that comes to you outside human birth is illegal and has no jurisdiction over you. The only power a satanic spirit have in your life are the ones you surrender to him.
But as soon as you say enough is enough, even the angels must obey. And no man can rule over the righteous when you realize your Preeminence as a New Creation. No man can rule over the righteous when you realize your Preeminence as a New Creation. Malignant celestial beings can’t harm you if your full of Christs authority.