Celestials are non-mortal, magical humanoids. Their magic, much like Infernals, is often considered different from Umumtu's "magic", even though there really is no difference. Celestials are simply able to survive and interact in the Living Realm to more of a degree that the other mortal magical races, due to the amount of Living Force they also tend to posses.
It would be incorrect to assume all Celestials are "good", despite their "angelic" imagery. This is a misinterpretation by mortals, assuming that light and angelic things are inherently "good".
Celestials possess the ability to shape-shift to a degree. Gender, race, height, eye color, etc. are all easily changeable. According to them, in their natural state they are tall with a light pink/purple skin tone and large "angelic" wings. Their hair is various pastel shades, and faintly glows.
However, as Infernals are, essentially the same race, it's believed that this 'natural form' is merely a cultural affectation, and not a biological fact.
Celestials are, for all intents and purposes, minor Gods and Godesses. While not as powerful as Dragons, they have a great deal of magical ability, and are able to do traditional divine things like miraculous healing, transforming mortals into other races/creatures, creating simple life (trees, plants, etc), and controling elemental forces.
The most well-known ability of Celestials is the ability to fly or hover, as they wish. They do not need to move their wings (as they actually play no part in the purely magical effect) though many use the wings for dramatic effect.
While they don't draw as much attention to it as their Infernal kin, Celestials are able to change any aspect about their physical bodies. Most well known is their winged appearance, however, they can change anything from mundane things like skin color, height, or hair length to biological sex.
As Celestials are a shape-shifting race, they are born without a biological sex. As they mature they naturally start expressing the biological characteristics of the gender they feel most comfortable with. However, it is up to the individual if they wish to associate with a particular gender or not. Gender-fluidity, non-binary and general gender queerness is rather common with Celestials.
Celestials do not age once they reach maturity, and do not die from sickness or disease. (They can be killed, however.) They do reproduce like other races, though at a very slow rate. Due to their ability to shape-shift any pairing of Celestials are able to bear children. Celestials can cross-breed with other creatures, though a pairing with any other magical race but an Infernal produces a sterile hybrid.
The only known hard limitation Celestials (and all magical entities) have is the ability to raise the dead. While it is possible for a mortally wounded, or recently deceased person to be restored to life, there is a very narrow window in which they can be revived, and it's believed this is because the person isn't truely dead for several minutes after bodily functions have ceased. However, once the window has expired, there is no known way to return the creature to life.
There are, however, soft limits on a Celestial's abilities. As with all magic; there is a limit to the amount of energy they can use over a period of time. After expending this energy, they will need to recharge their abilities. The more powerful the Celestial, the more energy they can use before needing to recharge, however, the longer it can take to recharge.
Because of the energy limitation, there are some things that are simply impossible for some Celestials, while being possible for others. However, even the most powerful Celestials are limited in the same way.
Celestials are, like all deities, prescribed domains by those of the Living Realm. Celestials are not actually bound to the domain prescribed them (unlike Umumtu and Veza) but instead the ones whose names are known tend to be particularly skilled at, or enjoy a particular facet of the Living Realm, leading to those in the Living Realm to confuse that preference for a domain.
Celestials were one of the first creations by Vexa and Umumtu when they created the world. Before the sundering of the world, Celestials lived along side mortal races. After the sundering, the Celestials and Infernals asked Umumtu if she would assist them in creating their own realms, the Celestial Realm and the Infernal Realm, respectively. While these are not true "realms", they are their own lands in the Magic Realm. They wished to live on their own, seperate from the other magical creatures, and wished to continue doing so even if her efforts to reunify the world were successful. Umumtu, reluctantly, agreed.
From their new realm, the Celestials found their own way to interact with the Living Realm. While they can easily visit (or live) anywhere in the Magic Realm, the Living Realm presents the same issues for them as for all magical creatures. With effort and practice they can open a portal to the Living Realm. Simply entering it takes great effort, and they are limited to hours or days before they need to return otherwise risk dying. However, if they have access to a source of magic (like nearby monsters) they can stay much longer.
Most Celestials believe they should simply focus on themselves and ignore the other realms entirely. They espouse a policy of non-interference. However, since the creation of monsters, that has been changing more and more. Even before the sundering, some Celestials had become fond of mortals and got enjoyment out of interacting with them. Now that the Living Realm is more open to them than it has been in millenia, they're remebering how much fun they used to have. They do have to be careful, though, because the danger of the Living Realm is staying to long and not being able to return. Such an event would be a death sentence for any magical creature.
Celestials are some of the most prolific of all the magical races, prefering to interact with others, despite their generally aloof nature. As such, most races still know of them, for good or ill.
Celestials prefer to come off as gods and godesses, than interact directly with mortals. Combined with the fear of being trapped in the Living Realm to slowly die, they prefer to remain aloof and dignified. This can often read as arrogant, and in the case of some, might be quite accurate.
Celestials had to be the favored creations of Veza. They are so full of life and light that it's impossible to imagine them as anything but her messangers. They are to be worshiped and revered.
It's hard to reconcile the peace and warmth these beings give off with them being magical in nature. It is easy to lose one's wits around such a creature; so easy it is to want to believe everything they say. However, ancient knowledge reminds us that they too are simply creations of the Goddesses with their own agendas.
It's not possible to hate a Celestial; who and what they aren just removes all negativity from your very mind. And for that, I do not trust them. No race is good in it's entirety. But it's hard to hold on to that in the presence of a being like this. Perhaps it's my own nature being reflected back to me that makes me doubt their goodness.
I have very little use for creatures like this. Too many other races fawn over them. While I understand why; it's hard to avoid wanting to do that in their presence. But Orcish will is stronger than their magic, and so we resist and throw them out on their immaculately sculpted asses.
Celestials? Hmm, no, I've never encountered one. They sound both terrifying and wonderful. Why, do you know one? Please, I'd love to meet them! I have so many questions about history that they could answer!
No? Pitty. Any creature that has been around since the world was founded would be a gold mine of historical corrects! I hope to meet one, eventually!
Celestials are often seen as the 'errand boys' among the other magical races. Publically, they lean into this, though amongst themselves to express frustration that unlike Dragons, very few come seeking their advice.
Our Celestial brotheren will do great things once they've learned the lessons of youth. Some of them already have. As a whole, however, they still remind us of ourselves when we were younger.
Oh, man, I love these guys! I mean, they're the absolute worst, and I'd just as soon punch one as shake his hand... but they're so easy to goad. You can just get under their skin with practically no effort. They're like the older sibling that you love to mess with, but really you just want... nevermind. They're just the worst, let's leave it at that.
I'm sure Umumtu knew what she as doing when she crafted them, though I fear they were more Veza's design than our Mother's. I've never felt comfortable around them; like they blame us for the sundering. It wasn't our fault. Who knew that would happen? Honestly, they need to get over themselves.