Shadow Galactica been played by two actresses, Haruko Yamaguchi and Megumi Wakamatsu. and appear only in Act 48 of the manga. Sailor Lethe is named for a naiad in Greek mythology, and for a river of the Greek underworld where dead souls go to forget their past lives before being reincarnated. Sailor Mnemosyne is named for the Titaness of memory, the mother of the muses, as well as another river in the underworld which brought remembrance and omniscience. Sailor Lethe has an attack called "Galactica Myosotis Alpestris", which she used to attack Usagi. Myosotis alpestris is the name of an alpine species
The Book of Souls purchase of Sanctuary Records in 2013. On 14 August, the band issued a music video for the song "Speed of Light", directed by Llexi Leon. In addition, the song was simultaneously made available as a digital download and was issued as a single-track CD via Best Buy in the US. "The Book of Souls" is the band's first album since 1995's "The X Factor" to use their original logo on the cover. The artwork was created by Mark Wilkinson, whose previous works for Iron Maiden include "Live at Donington" (1998 remastered version) and "Best of the 'B' Sides" (2002 compilation),