We've existed for centuries

We've existed for centuries. Not the beginning of time, no, but long enough to see the world evolve into what it has become now. A mass of crime and destruction, much worse than from our time.

We are what was never to be. A mix of the greatest evil and most good. A fusion of Satan and God themselves. We can fit in with demons or angels, and at the same time can't stay among them either.
We are called daengels. We are also known as damned angels. We belong in neither heaven or hell. We feed off precious stones and metals, but the thing that nourishes us best are souls. Of the Undead, more specifically.
My tribe, is, literally, the last of our kind. There are sixty-eight of us left, in my clan. How do I know? Daengels just do. We are aware when there are others. We connect through the souls. Not so that we can read each other's thoughts or know what the other is feeling, we are just aware of one another. My tribe is the last of our species. We have decided that we will dedicate our lives to finishing of those that harm mankind.
We were human once. Well some of us were anyways. Some of us are born when a holy person, or an angel itself, mates with a demon. That's one sure way produce our kind, a method that will surely get you an normal daengel. One that has normal powers. Such as changing of one's appearance, the ability to levitate, to teleport from one place to another, draw familiars in the form of our choice, and powers to heal, not only ourselves, but others as well.
If a daengel mates with a daengel, the child may be like it's parents, or it may be human, normal, or with few powers.
If a daengel mates with a human, the chances of the offspring being a daengel or having any power at all are very slim. The child will most likely be a normal human child.
If a daengel mates with a demon, the offspring may turn out like a normal daengel, but it is more likely that the child has more demonic powers.
If a daengel mates with a angel, or a holy person, the child, again, may turn out to be normal daengel, but has more possibility to have holy powers.
What kind of powers? I cannot say. Every child will vary.
A human can be changed into a daengel by swallowing our best food source, an Undead soul. Though people only did this when they were about to die at the hands of a vampire and it's ghoul was around. This ritual isn't performed anymore, no one knows about it.
We have liquid silver running through our veins, handy when it comes to dealing with vampires.