Well... Here is a little part from this MY world

Humans have been developing fast, they have created many new things what harm to the environment. Their inventions are turned against the other races in most cases. The humanity lost the contact with the nature, they don't have magical power. They have short life and they're weak but clever. They use their ingenuity to make harmful weapons not only to protect themselves but to destroy with it. Therefore all things which were invented by humans must be destroyed.

This kind of development must be stopped. The dark elves who are specialized for this task live in camps set up for them in small villages. The general unwritten dark elven rules do not concern them. They make the dirty work. Their community is strong and solidary, they don't keep contacts with the outsiders. Their basic principle is, that everybody is alike, there is not female dominance, and there isn't competition between fighters and magicians.

It is not possible to find them in daytime since they have hot eyesight, but to hide fromthem at night is impossible too.
They only and exclusively kill humans, they don't befriend with elves however they don't keep aloof from them. Everybody can enter into their village but no one is going to have authority there.
You may recognise them by their badge and their deep secular predators. These animals are kept by dark elves, as humans keep the domestic animals. These animals are clever, loyal and their smelling is unique. Their whiskers are the capital element of their nose. It is not possible to find them in daytime since they have hot eyesight, but to hide form them at night is impossible too. There is keratine on their head but it's stronger than stags' or rhinoceros' horn. Many tiny saw-edged teeth can be found in their mouth. Only their upper mouth is attached to the lung. They're fast, they crawl skillfully, they jump high. They appear in many sizes: they can be as small as a mouse or as big as a lion but there were big types as bear. The horn and its color depends from their habitat. Their origin is unexplained but people believe that these animals were bred for hunting in the age of Experimenter.

So, what is the real task of these dark elves? Their principles what must be followed:
To search (it). To find (it). To destroy it. To send a message.

-To seek out the possible places where the science outstripped the imagination, where the power of the magic died, where the things is out of order according to order.
-To find the bastard embodiment of the science. To find who created it. To find the
memoranda from the device giving rise to the fear. To find who were in contact with it.
-To crush everybody. To burn the notes. To burn the devices. To burn the humans. To pursue them while who is able to use the science don't die without exception.
-To send a message to the next generation. To pin skulls into ground as a trophy onto a picket, to intersperse the burned houses with carcasses. Be this a message about the future is in their hands.

They don't do it for fun. They don't fun on it. They don't celebrate the success.