Mythology and Etymology
The ability "Nosferatuan Thirst" is likely based on the main character of the 1922 movie Nosferatu: A Symphony of Horror, an unauthorized adaptation of Bram Stoker's Dracula. The names of characters and places were changed due to the studio's inability to gain the rights to the novel.
The origins of the word "nosferatu" are largely unknown. Some argue that is is a variation of an Old Slavic or Proto-Slavic word. However this is dubious due to the fact that there is no known source in any Slavic writing or literature that would support this argument. Other arguments put forth Latin origin, but again, this has yet to be proven with absolute certainty.
See also: Blood Brothers Event