Sailor Moon S is considered one of the darkest story lines in the series, partly due to the villains' ultimate goal of destroying, rather than conquering, all life in the world, as well as ethical themes of sacrifice. The arc is characterized by the appearance of three new Sailor Senshi: Sailors Uranus, Neptune, and Saturn. It also reintroduces the character of Sailor Pluto and gives her a civilian identity, Setsuna Meioh. In the anime, Chibiusa is seen for the first time in her capacity as Sailor Chibi Moon. The series antagonists are the Death Busters, led by mad scientist Professor Tomoe and the Witches 5.