All angels possess the same basic abilities. All angels, with the exception of the Dark Angels of course, use discretion when displaying these powers. Most angels are not prone to show off though some of the archangels are known to on occasion. They can appear amongst humans with or without wings at their own discretion. Obviously when trying to blend in they appear without wings though some simply choose to cover their wings with coats. The wings are used for flight but not in the same manner as any earth creature. An angel needs simply to spread his wings out and they can instantly take flight. All angels are stronger than humans, but the archangels are the strongest. Angels can appear and disappear at will. Their bodies cannot be physically harmed by any earth weapon. Magic can hurt them, though very few humans possess enough power to kill them. Angels can be hurt and killed by other angels though. Angels, including the Dark Angels, have weapons created in heaven. These are usually things such as swords and other weapons of that nature. They were used in the war against the Dark Angels and are very deadly to angels. Angels, however cannot die in the sense that humans do. When an angel is destroyed he loses all his powers and his memory as an angel and is reborn as a human. Dark Angels however do not. After their fall from grace they lost certain abilities as well. They cannot willfully become mortal. All of their wings were cursed to be black. When they are destroyed, they become one of two things, shapeless, bodiless, beings that usually proceed into a state of nonexistence though in rare cases these struggling spirits have been known to possess humans. Some however are reborn as an earth creature known as the demon. They can still appear in the physical realm, though they can't appear without wings so they are easy to spot and are currently doing most of their work in secret.
Angels have the ability to at any time willfully become a mortal human and sacrifice all of their angelic powers though retaining memory of their life as an angel.
Also angels do not feel in the sense that we do. They have no sense of touch, smell, or taste. They hear and see somewhat like we do. Though their sight and hearing can pick up things that a human's cannot. Along with being able to become invisible they can make it so that humans are unable to feel them. Even when visible they can make their bodies matter less and a person will walk through them just like air. Angels are capable of feeling emotions. They are sad, angry, and happy just like a human. But in addition they have the ability to sense these in others. They can also sense when a person is in pain, or is hungry, or even just out of breath though they themselves can't feel these things. This is something they just simply know.
Angels cannot make themselves invisible or matter less to other angels though. The best way to hide from an angel if you're one yourself is to appear in human form, without wings. Angels sense things through the spirit of a being, and essentially there is little difference between angel spirits and human spirits.
Angels also have some telepathic ability. They can speak to each other telepathically and if they choose can speak to humans telepathically. Though most angels prefer appearing to them in disguise.
Angels can also appear in animal form. Archangels can appear as a lion or as an eagle. Seraphim can appear as doves. Dark Angels can appear as snakes. Cherubim...I have no idea.
(The Cherubim play a minor role in the game. Heaven and god also play a minor role. Our game should be mainly concerned with the angels already "stationed" on earth to protect it. Like City of Angels they pretty much live on earth. I think if we really concerned ourselves with heaven or eden or whatever it may be, things could get complicated quick.)
All angels are born essentially the same. Angels have gender but do not reproduce in the same manner that humans do. Angels are technically created (by god or whoever)and not born. Angels do not marry though it is not unheard of for two angels to grow close. Angels grow up physically and mentally quicker than humans. By age ten, they would appear to be a human in their mid twenties. At this point they stop naturally aging, though they have the ability to make their bodies appear any age, this ability is usually only used when amongst humans. At this point they are given a choice of two things, what type of angel they want to become and their initial wing color. This color is permanent however, with a few exceptions. Archangels are granted metallic colored wings depending on rank. Cherubim are granted iridescent wings, depending on rank. Seraphim are granted two more sets of wings, depending on rank. These are always white. They can switch willfully between the two, but usually and especially archangels choose not to.
Dark Angels depending on their parents will become either Archangels or Seraphim.
Nephilim are completely different. They are children of an angel and a human. All of them were the result of Dark Angels though it is not known for certain how this was possible. Physically, for the most part they are just like humans. Capable of being hurt and killed like any human. They possess all human feelings but no extra sensory angelic feelings. They must breathe, eat, and sleep, unlike their angelic fathers. The only thing that sets them apart is that they require below average food and sleep yet exhibit above average strength and speed. Not superhuman but noticeably above average. They also have wings but they cannot be used for flight since they expend so much energy. They can be used for gliding but an extended flight would take a great deal even out of this creature. Even so with these abilities they were very dangerous to humans, as was the Dark Angels intent. Most were destroyed in the war, but some lived on. Some tried having normal lives but most were outcast and feared. A few live on currently in the outskirts of habitable land. Some lived with various nomadic human tribes, some even marrying and having children with humans.