Pharaoh 90

Pharaoh 90 is an evil force from another galaxy. He is the boss of Mistress 9 and Doctor Tomoe / Germatoid, and therefore is the final antagonist of Sailor Moon S. He has the appearance of a gigantic dark energy orb.

Character biography
Pharaoh 90's galaxy was seen in a dome by Doctor Tomoe, and so he and Germatoid caused a lab explosion, nearly killing Tomoe and his daughter Hotaru, and promised their survival if Tomoe worked for him. Germatoid then possessed him.

Tomoe then began setting out to find the Purity Chalice in order to summon him from his galaxy so he could destroy the earth by bringing the Silence about it. Eventually, Mistress 9 got the Purity Chalice and summoned him. Sailor Moon attacked him as he was moving toward Earth, but her energy beam didn't even affect him, and he countered with a massive red energy beam. He then arrived on Earth and began bringing about the Silence, destroying everything around him.

When Hotaru destroyed Mistress 9 and awakened as Sailor Saturn, she explained to Sailor Moon that the only way to destroy him was to enter him and destroy his core. Seemingly, Sailor Saturn, as the Sailor Scout of Destruction, was the only one who could do so, as no one else can even go near him without being destroyed. However, she revealed that Super Sailor Moon could also destroy him, but as the Purity Chalice was destroyed, and no chance of transforming into Super Sailor Moon, only Sailor Saturn could. Sailor Saturn entered Pharaoh 90 and tried to destroy his core, but he fought back. Either he nearly killed her, or she was close to using her power to destroy him, which would destroy her in the process.

Sailor Moon then received power from all the other Sailor Scouts (even Sailor Uranus and Sailor Neptune except Sailor Mini Moon and Sailor Pluto), and entered Pharaoh 90. She was able to destroy his core, and he exploded into nothingness, gone forever. Sailor Moon survived, and managed to save Hotaru as well.

Attacks
Pharaoh 90 can shoot a massive red energy beam, and can bring an evil force called the Silence about that can destroy anything.

Trivia

 * Pharaoh 90 is never referred to in the anime as "he". Instead, the pronoun "it" is used.
 * Pharaoh 90 is the only one of the final antagonists who is destroyed that is not killed in a beam struggle.
 * There is some confusion as to whether or not it was Germatoid who spoke to Doctor Tomoe after the explosion, or if it was Pharaoh 90, implanting Germatoid's Daimon pod in Tomoe. It is likely that this was Germatoid, however, from the way he says "Your body will belong to me". However, Germatoid clearly has a Daimon pod, as evidenced when he is destroyed.