The band's/project name is the Greek capital letter " Y " Υψιλον (upsilon). Y is known as Pythagoras' letter, because the great mystic Pythagoras used it as an emblem of the path of virtue or vice. Musically the project moves within the strict boundaries of black metal, possessing explicit influences from the most significant bands of the genre belonging to the first, second and third wave and which greatly affected the style of black metal both musically and aesthetically. In terms of subject, the lyrics refer to occultism and mysticism.