Icathian Lycanthropes

It is not sure if this is a race in itself, a racial subtype, or simply a group of monsters. They certainly can breed with 'normal' people, but after three or four generations of interbreeding the descendants show no trace of their origin.

Creation

You may want to see the parts on High Elves and Afterlife first, but the main point in short is this:
- the High Elves are immortal, and have no Afterlife, simply cease to exist when dead
- the mortal races are indeed mortal, but after their death spend their time as spirits. While they are in the same world as before, it is not the same to them, and they see and learn more of the world than they could in their life. But slowly, unavoidably, they change into something else.

Obviously, while having no desire to die themselves, the Elves envied the mortals, and wanted what was denied to them. If not experienced personally, then at least seen and understood how it works, what can one learn in that 'Afterlife'.

The primitive tribes of mortals were for a long time in contact with their ancestor spirits. The research was unfortunately disrupted as their society collapsed, absorbed by the splendid, powerful and advanced High Elves. With no tribal identity to flock to, the spirits went their own ways after Death.

Those practicing shamanism found a way to preserve their powers: they started to worship powerful natural spirits, those they could understand and accept. The research renewed, the 'coolest' were the potent spirits of predators. Given the natural order of things (always new being born, and always some dieing) they were powerfully present in the Spirit World. The unrestrained freedom of a wild animal combined with with sharp supernatural senses, and something resembling an intelligence were irresistible to the Elves. They had to see it, they had to FEEL it...

...and so they made experiments. A shaman has contacted its chosen spirit, the powerful magic of Elves has made the contact permanent. While the poor man or woman stumbled on the brink of insanity, the researchers had a great time reading his or hers mind, and feeling the wild emotions. In the end, the experiment became a popular pastime, and stayed so until the revolution. But that's another story.

Lycanthropes

As a life-form, they are long-living, some known to live over five centuries and still able-bodied. With such a strong ally of their protecting spirit, physical damage harms them little. On the other hand, once they are dead, they are dead forever: their animal part returns to their Spirit, their mortal part expires nigh to immediately, very little staying behind.

Personality-wise, they all dislike being bound to a place or under command. It must not be forgotten they are strongly influenced by their Spirit. A young (or 'fresh') lycanthrope has serious problems to stay in control, and responds to strong stimuli like an animal would.

The older ones have lived for some time with the Spirit. While their body gets slowly weaker, their wisdom is great, and their knowledge of the spirit world and the natural world is deep indeed. Becoming calmer, and strongly in control, some choose to study and record history of their kind and other fields of study. They even record the history of other races, and (given their long life span), it is quite accurate. It is said the truly old ones loose their scent, and can move freely between the animal kindred, even between mortals without a trace; on the other hand, they have more and more diffilcuty escaping their knowledge of and connection to the Spirit World.

While most are fierce individualists, many conflicts with misunderstanding mortals caused them to form a half-loose alliance. Their lobbying was hardly to be resisted as it took centuries, and large forested areas still exist within the (now former) kingdom, formally belonging to the nobles or king himself, actually under their protection. Watch out for those foresters, some may be more than they appear.

Legends claim lycantropes are secretive madmen, that need the thrill of the hunt, and fresh, bloody flesh, best ripped from a still living victim. A true hunter does enjoy the hunt, though does not necessarily attack or kill each time. Some are content with hunting animals, some hunt humanoids for a time, but let them leave freely. Some hunt for the kill. If you find yourself in the game of Hunter and its Prey, be careful! A single wrong step can make it deadly serious.

As for the bloody flesh, meat is certainly attractive to them, but the form is of individual choice. Some tend to be neat around meat, cutting into slices and baking it, adding a bit of this spice, and a bit of those. Not a few of them, when around 'normals', ostensibly enjoy vegetables, bread and all that is not meaty.

Special abilities: besides an unnatural rate of heling, and what else comes from the link with a potent anima spirit, lycanthropes may be partially resistant to magic. Especially magic affecting the mind fares poorly against them, due to their unusual psyche being interwined with something else.

Infection and Spreading

It is all nonsense about 'The Disease', and 'The Curse'. A bite or scratch itself is only as dangerous, as of any wild animal. But this is no mere animal, and what it touches can be marked by the spirit world. If you are just a helpless victim during an attack, and somehow survive, nothing special happens. But if you fight back, if you resist the violence, the fiercer, the better, the predating Spirit may recognize you as one of its own children... and call upon you.

Thus you may start to feel its call, find yourself under its influence, and slowly transform into that 'beast'. The cure is actually as simple as impossible for most: reject the spirit of a predator from your life, from your very soul. Those few that are able to do this, become monks in their own right, often hermits in their pursuit of not harming anyone. Being touched by spirits once, some may choose to become a shaman. Some will be haunted by the spirit world for the rest of their life.

As the 'change' is at first little controlled by the victim, the normal society is always terrified of the Disease, and seeks to cure or kill anyone infected. While there is in fact no cure, as there is no disease, the medicine and rituals which tend to be used in reality try to brainwash the victim... which may lead to a success. The victim will be deeply changed afterwards.

The inclination towards lycantrophy, and a certain closeness to the Spirit World is passed to the children of a lycanthrope (rarely, it can pass even to adopted children, without any special attempts). Whether it develops, depends on their personality and life.