the WORLD Ruler is Nightmare's fourth full-length studio album. Nightmare's experimentation with the styles of electronica, ambience, and usage of live brass began in this album. Three different versions of this album were released: a CD-only version; a CD+DVD version; and a bonus CD, DVD and photobook pack. It peaked at #6 in the Oricon Charts. The tracks "The World" and "Alumina" were featured in Death Note as the first opening and ending songs, respectively.