Darkness, My Old Friend

Darkness, My Old Friend is the 36th episode of Sailor Moon S. It was preceded by Who's Really Who? and followed by Second Chance.

Plot
Mistress 9 begins to awaken Pharaoh 90, the power source for the Heart Snatchers and the Deadly Silence, and once she gets the Purity Chalice, he will be able to come to Earth and destroy it with the Silence. Sailor Uranus and Sailor Neptune attack Mistress 9 with World Shaking and Deep Submerge, but Sailor Moon takes their attacks (as killing her will kill her host, Hotaru, as well). Mistress 9 wraps her hair around Sailor Uranus and Sailor Neptune, traps them inside a giant statue, and begins to strangle them with her hair, telling Sailor Moon to give her the Purity Chalice or else she will kill them both.

Doctor Tomoe appears, no longer possessed (due to the death of Germatoid), so Mistress 9 begins to strangle him. Hotaru begins to awaken inside Mistress 9, and fight against her. Soon, it seems as though Hotaru is in control, and she releases Tomoe, Sailor Uranus, and Sailor Neptune. She says she needs the Purity Chalice to return to normal. Sailor Uranus and Sailor Neptune are sure it's a trick, but Sailor Moon gives it to Tomoe, who gives it to Mistress 9. However, it turns out that Mistress 9 was indeed tricking them by pretending to be Hotaru. She uses the Purity Chalice to summon Pharaoh 90 to Earth, and the Purity Chalice is destroyed in the process, along with the rest of Mugen School.

Sailor Moon uses Moon Cosmic Power, shooting an energy beam at Pharaoh 90 as he draws closer to Earth, but he is completely unaffected, and blasts her with a red energy beam. He then attacks Mistress 9, having no further use for her since she delivered the Purity Chalice to him, but Sailor Moon and Tomoe protect her. Pharaoh 90 arrives on Earth and begins to bring the Silence about to destroy it, overpowering the other Sailor Scouts and their Sailor Box, and destroying the Daimons in the barrier.

Hotaru begins to regain control. Mistress 9 tries to fight her, but Hotaru's memories of her father and Rini are too powerful, and combined with her already weakened state and shock from Pharaoh 90 betraying and attacking her despite her loyalty in providing him the Purity Chalice, Mistress 9 is completely destroyed, the black star on Mistress 9's forehead shattering as the symbol of Saturn appears, obliterating her once and for all. Hotaru awakens as Sailor Saturn and returns Sailor Mini Moon's Pure Heart to her. She then tells Sailor Moon that she must destroy Pharaoh 90 by destroying his core. It is impossible for anyone else to get near him, but if Sailor Moon could transform into Super Sailor Moon, she could have helped, but she can't become Super Sailor Moon anymore, because the Purity Chalice is destroyed. Sailor Saturn also reveals that the reason she is feared and known as the Sailor Scout of Destruction is because she has the power to destroy a planet, however, using her power will kill her. When Sailor Moon still tries to help, Sailor Saturn forces her to stay back by pointing her Silence Glaive at her before heading into battle to stop Pharaoh 90.

Sailor Saturn enters Pharaoh 90 and begins to fight him from the inside, with Pharaoh 90 grunting and groaning as he takes damage from Saturn's attacks. Sailor Moon tries to transform, saying "Moon Crisis Power Transform!", but it does not work without the Purity Chalice. Sailor Mercury, Sailor Mars, Sailor Jupiter, Sailor Venus, and even Sailor Uranus and Sailor Neptune power up Sailor Moon, and she transforms into Super Sailor Moon. She enters Pharaoh 90 and destroys his core, and Pharaoh 90 explodes with a final, pained scream and groan, completely destroyed forever.

Super Sailor Moon reappears, battered and bruised, with a baby, which is Hotaru reborn.