Angels are the main supernatural in the Fallen novels. Though there are three types of angels, they're all solely angels. Daniel and Lucinda are the only two angels who are known to be 'neutral' or pick neither sides. This resulted in the two being cursed for their decision.
"There were endless tiers in Heaven, each level teeming with alcoves and winding paths fanning out in all directions under a honey-colored sky. The air was perfurmed with nectar welling in delicate white flowers springing up in delightful groves. Their round blooms fotted all of Heaven's nooks and crannies, looking something like the ancestors of white peonies. Orchards of silver trees bore the most delicious fruits that had ever existed. A meadow rolled into existence, dividing the orchard into two." - Lucinda, describing Heaven for the first time
Not much is known about the Angel's home. There is a meadow that separates between orchards of fruits and there is a place of thrones for the Throne/God and for the eight Archangels. The ground was described as 'cloudsoil' - more than likely meaning Heaven looked as if it were upon clouds, on white soft ground. The sky is the color of honey and there are flowers much like peonies all across Heaven.
When Lucifer had rebelled against the Throne, the meadow had a line drawn between and the angels were forced to choose between both Lucifer and The Throne. When Daniel and Lucinda made their decision, The Throne had thus sent the angels falling.
Very little is known of Hell, only that is Lucifer's kingdom and that this is were most Demon's reside. However, in the upcoming Fallen novel, Unforgiven, it is seen that Hell has it's personal food court and is quite normal, much rather than the idea of flames and whippings as many believe.
The Fall happened in the fields of Troy, Turkey. The Fall was a result of the angels falling from Heaven. There were sizzling craters, angel dust, trees were on fire, and a stench of rot. Many of the Fallen angels were hurt, their wings broken and bodies battered. Lucinda had also been the only mortal at that sight, and she had also died that very time for the first time.
Lucinda describes Angels in Rapture as spiritual matter, but given the bodies of the not-yet created mortals. Each angel had their own set of unique wings that often extend far more larger than their beholder and each angel has a glorious beauty. In Passion, it is also revealed that if a angel reveals it's full soul and glory to a human, they will perish.
The wings of each angel, however, vary of their side. If the angel had chose The Throne, their wings would stay the same - White/Translucent. If the angel had chose Lucifer, their wings would become gold. If the angel is an Outcast, their wings would be weak and a brown or black color.
Types and sides
There are only three types of angels and two sides for the angel to choose from. But, all angels currently - Except for those welcomed back into Heaven - Are Fallen angels. Fallen angels are not welcomed into Heaven and
Good (The Throne)
This side is the main choice among angel, considering it is known as the 'good' side and is their main home. The angels on this side can be either Fallen Angel or they could be angel who had fell but were granted access back into Heaven after. They keep their white wings and gifts. Known Angels that chose the "good side" are: Annabelle Alter, Arriane Alter, Francesca and Gabrielle Givens.
This side is the opposing side of the Throne, considered to be the evil side and are called demons. There is also a part of this side known as 'The Circle'. The Circle is supposed to be Lucifer's inner circle, meaning to be those at his side, close and trustworthy. Each Demon in the inner Circle bear a sunburst mark on their neck. Known Demons who are apart of the Circle are Cam and Tess Demons also lose their white wings and are replaced with golden wings, Lucifer is the only known demon who retains large black wings rather than golden ones. Demons also seem to have golden rimmed eyes at times and are skilled with Announcers. Known Angels that chose the "bad side" are: Cameron Briel, Tessriel, Steven Filmore and Mary Margaret Zane.
Outcasts are angels that switched with the side of Lucifer, but after the war they tried to get back into Heaven. After being denies access, they went to Hell but were also denied access there. After such, they became their own group, having the angel Azazel - Who is the only Starsmith left - crafting weapons. They retain pale/all white or black eyes and have all black wrecked wings.
Very little is known of the angel's gifts. It is assumed they are very strong and skilled fighters. There are several times throughout the novels when the Angels show they have gifts. Gabbe and Arriane first demonstrated their gifts when they summoned lights, close to Announcers but are much like Heaven's warriors. It is unknown what they're called. Cam also showed his Demonic gifts by summoning Announcers for battle in Fallen. In Torment, Daniel showed that he had the ability to shrink down items.
While Angels are shown in the Fallen novels to be nearly indestructible and incredibly strong, they still bear some weaknesses.
Since Angels have human bodies, they still have human weakness except that they cannot be killed. The first demonstrated weakness of an angel was shown by Daniel in Passion, in the life of Tibet when he attempted to commit suicide and shattered every bone in his body before he was found by Gabbe, who put him in stilts and healed in back together. Arriane also mentions that Angels cannot bleed, so it is unknown if angels have a live body.
Killing an angel is very hard, and there is only one way to kill an angel, which is by Starshot, which is one of the only known weapons that can kill a angel. When they die, they turn into dust.
It is unknown whether female angels can carry children, but angel men can have sex with human women and their off spring would become half angel, half human - A Nephilim.
Nephilim are a result of a male angel and a female human relationship. They often retain gifts but often bare no wings. Their lives are much like humans, however. They need to sleep, eat, and such - Much rather than angels. Most known Nephilim go to Shoreline Academy in the 'honors classes'.