Out of all of the elves you have listed, you seem unsure of what a shadow elf is.
After much meditation as to find my true elven identity (as to which you have helped me look for) the term shadow elf has come to me many times so i can only tell you what i know of my powers and self.
We are not the dead elves or sleeping children waiting to come. We are an offshoot of wild elf that has learned to adapt to the darkness without losing our heritage to anger as the drow have.
i stand at five foot nine inches,with brown hair , blue /orange eyes, and pale skin, as with other elves i am thin. such as sea elves are infused with the water element,and wild elves are infused with the earth element, i am infused with a form of the spirit elemental known as the void or the vortex,and most of my magicks are done through means of draining power from one source and directing it as i see fit.
i was naturally born with this gift, and it works with all forms of energy that are magickal….it is a form of camouflage. whatever group i am with i can use their powers myself….like a shadow in the night its hard to notice because it is made from the same darkness as the night. and by using my gifts i become the same as what i am with….that is power wise physically i am elven.
Like the drow, bright light weakens me and burns my eyes.I can usually be found wearing dark sun glasses..im not sure if we naturally speak the elven tounge or even have a toungue,but im also newly awakenened. i hope this helps it sounds like old memories that are right .