After playing as a Monster of the Week series for the first season, Supernatural took on a more Biblical tone in season two and moved onward. Honestly, if there were demons infesting the Earth, it was only a matter of time before angles made their appearance as well. And what the show did better than anyone could have believed was making the angels just as bad as the demons that they hated.

The two most powerful antagonists on Supernatural were, in fact, archangels with the holy one, Michael, almost worst than the fallen one in Lucifer. Add in all sorts of minor angels and a major ally in Castiel, and the show was soon overflowing with Heaven's army. With so many angels running around, here are 10 rules the angels in Supernatural have to follow.

10. Requires A Vessel While On Earth

10 Rules The Angels In Supernatural Have To Follow

The big reason that Azazel attacked Mary Winchester and dropped his blood into Sam's mouth was to create a vessel for Lucifer. That is because Lucifer and Michael both needed a vessel in order to walk the Earth and set out upon their final battle. That is something that all angels need — a vessel that allows them to walk the Earth.

This is similar to demons, who also have to have a vessel to operate on Earth. Interestingly, while angels can take on a basic vessel and walk the Earth, an archangel is different. They are so powerful that only true vessels can hold them, any other will decay or explode.

9. Must Have Permission For A Vessel

10 Rules The Angels In Supernatural Have To Follow

A demon can take over anybody that they can control; they can do this without the person even giving them permission. However, due to the grace of an angel, that is not possible for them. The only way that an angel can take over the body of a human is if that human gives them permission to do so.

Not only that but if a vessel decides that they no longer want the angel in them, they can revoke the permission. They can then kick the angel out while blocking their way to come back into them (although it is very hard to overcome the angelic possession).

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8. Only Possess Certain Humans

Myers Briggs Personality Types Of Supernatural Villains

It is also very difficult to find humans that can serve as true vessels for an angel. Castiel once said that it was very hard for him to find a human host that was durable enough to contain his might. It is even harder for someone as powerful as Lucifer or Michael.

When Lucifer was preparing Sam to serve as his vessel, Sam had to drink demon's blood because he needed it to keep his body from exploding once Lucifer took over. The name for these bodies are true vessels, which is most important for archangels. Sam Winchester is Lucifer's true vessel while Dean Winchester is Michael's.

7. Can't Show True Forms

10 Rules The Angels In Supernatural Have To Follow

An angel is not able to show their true form to a human. According to Castiel, his true form is gigantic — the size of the Chrysler Building. He also said that their true form is basically nothing more than waves and lights — pure energy. Other instances are pure white lights or even luminous smoke for those without wings.

Lucifer, and presumably other archangels, are dangerous to anyone who sees them in their true form. When Lucifer showed his true form, it destroyed an entire convent. To emphasize the danger, Pamela Barnes used her powers to see what Castiel really looked like and her eyes burned out, blinding her.

6. Must Remain Loyal To Heaven

Myers Briggs Personality Types Of Supernatural Villains

God created angels and they have no option but to remain loyal to Heaven. Their powers, which are many, are restricted by this loyalty. If and when an angel betrays Heaven and rebels, their powers begin to wane and end up vanishing over time.

Archangels such as Lucifer and the seraphim do not suffer from this condition and restriction, as Lucifer rebelled but remained one of the most powerful beings in Supernatural history. With that said, regular angels must always remain loyal to Heaven or they will eventually lose their grace and become mortal beings; powerless and nothing more than another human.

5. Fallen Angels Lose Grace

10 Rules The Angels In Supernatural Have To Follow

When an angel falls, they lose their grace. When it comes to the difference between angels and mortals, angels have grace and humans have souls. It is the grace of an angel that provides them with Enochian magic.

When an angel falls, they lose their grace and also lose their powers. These are seen as what appears to be falling meteors, and when an angel falls, they also lose their wings. There is also another way to lose grace: when it is removed by slitting their vessel's throat with an angel blade and drawing it out. If an angel loses their grace but never fell, they can regain it.

4. Require Wings To Teleport

10 Rules The Angels In Supernatural Have To Follow

When an angel teleports somewhere, it is usually accompanied by the sound of flapping wings. That is because angel's wings are what they use to teleport from one place to another. According to Zachariah, humans cannot see an angel's wings because their senses are too dull to view them. However, the wings are seen in shadows and are burned into the ground when an angel perishes.

When an angel loses its wings and is unable to teleport, they can still move around as blue luminous smoke. After the Big Fall, all angels lost the ability to teleport outside of upper-level angels, like Lucifer and the Grigori.

3. Communicate Through Angel Radio

10 Rules The Angels In Supernatural Have To Follow

In season four, Supernatural introduced a new form of communication. The angels are able to send out messages to each other using what Dean Winchester referred to as "angel radio." This can also be used as a weapon, as Castiel used angel radio to broadcast Metatron revealing his dastardly plan to all other angels, turning them all against him.

For some reason, angel radio is extremely painful to the Nephilim Jack, who is unable to listen to it without getting an excruciating headache. For all other angels, this was a way to gather the troops when they needed to congregate somewhere.

2. They Must Remain In Heaven

10 Rules The Angels In Supernatural Have To Follow

Angels have to remain in Heaven. While some can take on Earthly vessels, they must remain in Heaven to protect it. The only way that an angel can maintain its powers is if it remains connected and loyal to Heaven. Their job is to guard the souls in Heaven and if they leave, they are going against their duties.

However, that was proven when Metatron caused all angels to fall from Heaven. This proved fatal to many of the angels and others became trapped on Earth, most losing their wings while still keeping some of their powers since they were expelled. Since the Fall, angels are now an endangered species.

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1. They Must Keep Their Faith

10 Rules The Angels In Supernatural Have To Follow

Dean Winchester was speaking to Anna about angels and God. He asked how many angels had actually seen God and she admitted that there were only, like, four of them who've seen God personally. She was not one of them. Dean then asked how she could even know that God really existed if almost no angels had ever seen him.

Her answer was frightening. Anna told Dean that angels have to take his existence by faith. If they do not have faith, they will have their lives taken from them. While humans have free will, an angel who does not believe is no longer allowed to live.