More info on races|COP3

After a quick chat with Annabeth I've decided to change Orcs to some sort of water creature race, mostly because Orcs been done many times before. However I'd like to include them in the futher development of this project (extended practice perhaps).
I've looked into various water creatures, like mermaids and syrens. The following 3 got me really interested:

• Nixe - water spirit that can shapeshift into different creatures; German, Norwegian, Swedish mythology; play songs to drown people in lakes; usually harmless, but they can be malicious; both male and female can shapeshift and lure humans with their beautiful songs, can take human form but there will still be some clues indicating their origins (like ears or wet clothing);
• Rusalka - water nymph, female spirit in Slavic mythology (''red-haired girl'' is the direct traslation of the word русалка ); originally seen as a friendly creatures linked with fertility, however, after XIXth century they started to be assosiated with unclear spirits, somehow dangerous; rusalkas are women who commited suicide by drowning or who were violently killed by drowning; during Rusalnaya (Rusalka Week) they're the most dangerous and drag swimmers into the depths of lakes and rivers; Rusalkas hair are usually red or golden, very long and wet, eyes are blue or turquoise;
• Hulder - seductive forest creature; Scandinavian folklore; male and female, both can shapeshift; females have long gold hair and wear flower crowns, however they also have cow tails; usually friendly creatures, keepers, like to be treated with respect;

I've decided to go with Nixe race, although I really like the story of two other creatures.
Since Nixes are water creatures living in lakes and rivers, the whole conflict between two races is very tense. Most of the technological artefacts are located near lakes and rivers, which makes human attacks often (afterall they're the ones who posses enough knowladge to use it). Nixes aren't a warrior race, but use their shapeshifting ability very well, by changing into other creatures, like water-wyrms, to attack boats. Moreover, with their enchanted song, they kidnap young kids from human settlements.
Nixes live as a small tribe, Lorelei being their queen/ruler, even tho she doesn't like to be addressed this way.

Human race, as mentioned before, in this region, is far more advanced, but due to the limited access to technology, still locked in what could be described as mix of medievil Germany with cruelty of Vikings. Outfits heavily inspired by both eastern MMORPGs (Final Fantasy-esque) and western fashion from that time. Military orientated, tyranny from the king, both males and females are trained to fight and become warriors. Some of well educated men can become mages (need to come from high clans and be able to use magic) and their daughters, who also posses magical powers, can become dancers.

As for now, my design task is to come up with characters for both fractions - warriors, mages and dancers for human race and male/female versions of Nixes plus their ruler Lorelei.