The Nasgareth may look like elves, but instead were created by an entirely different divine being, which admired the elvish looks and traits, but wanted to create his own army instead. One without Love.
Diseased people, (leprosy or any other such fear inducing disease) when traveling, will often times wear a cloak that entirely covers their body and ring a bell as they travel, used as a warning for any others to stay away. Could be used for a disguise or safe passage. ... you meet strangely cloaked people, sometimes ringing a bell. "Please give us something to eat, mighty heroes!" This is time to show how good they are.