Hmmm, how does Sailor Astarte's story go? I guess it starts in the Sera Myu Musical she first appeared in, Transylvania No Mori. Which is about the two main bad guys Death Vulcan Shiba and Lillith. It's about vampires vs the Sailor Senshi. This is a sequal to the last musical where the main vampire Dracul gets killed, and in this one he gets resurected. Here's my brief summary of the musical based on the revised edition of the musical.

          Michiru (Neptune) announces that she has a concert in europe and all the senshi are going along with her. All the while many of them are complaining about a test they have to take. Their teacher, a nun, says they can't go unless they pass the big test, She also introduces Shiba Shingetsu Astarte, a transfer student. Rei proposes that they go to thier temple and study, they go there and notice that the temple is attacked by vampires. This is when the Senshi get an invitation to a Romani Castle to battle the vampires. So the senshi go to europe, and arrive in Romania where Michiru's concert gets cancelled. The senshi go to thier hotel to be attacked once again by the vampires. The vampires leave, and meanwhile the badguys converse with the Sammael Quartet (Which are known as the Amazon Quartet in the anime.) Chibi Usa comes by, and befriends the Quartet. She converts them to be on their side. And so the Sammael Quartet turn into the Sailor Quartet to fight against the bad guys. Uranus, Mars, and Jupiter later get bitten and turned to vampires. During a battle, Sailor Astarte comes out of no where and uses her attack "Solomon Jihad" to break the magic sword of Sammael. Then she returns to her other personality, as Death Vulcan throughout the most of the musical. Eventually the vampires are beaten, and Sailor Moon cannot "purify" Death Vulcan to turn her back into the good-hearted Shiba. And Sailor Astarte can never appear again. I should also note Sailor Moon turns to Super and Eternal in the Musical, all of the senshi were included even though Pluto and Saturn didn't do much. Another thing I want to add is that the musical was extremely long and hard to follow. I could not follow the ending very well to know what exactly happened.

    The full title of the Musical in english is called 'The Forest of Transylvania: New Appearance! The Soldiers protect Chibi Moon'. It's full Japanese title is 'Transylvania no Mori: Shin Toujou! Chibi Moon wo Go ru Senshi Tatsu'.  Which came out in the Summer of 2000. The second and last Musical Sailor Astarte appeared in is called in english the 'Decisive Battle/ the Forest of Transylvania (the Revised Edition): The Strongest Enemy: Dark Cain's Mystery'  and it's full japanese title is called 'Transylvania no Mori -Kaiteiban- Saikyou no Kataki Dark Kain no Nazo' which came out during the winter of 2001. Usually they are just called Transylvania no Mori, and Transylvania no Mori Kaiteiban.

Tsukino Usagi/SailorMoon: Kanbe Miyuki 

Mizuno Ami/SailorMercury: Izawa Mariya 

Hino Rei/SailorMars: Kanda Eri 

Kino Makoto/SailorJupiter: Kuriyama Emi 

Aino Minako/SailorVenus: Nakamura Yuki 

Tenoh Haruka/SailorUranus: Takagi Nao 

Kaioh Michiru/SailorNeptune: Asami Yuhka 

Meioh Setsuna/SailorPluto: Hosaka Yuhko 

Tomoe Hotaru/SailorSaturn: Tomioka Mario 

Chiba Mamoru/Tuxedo Kamen: Hidemasa Edo 

Chibi-Usa/SailorChibiMoon: Izawa Arisu 

Cere Cere: Eguchi Shiroi 

Pala Pala: Nishijima Kurumi 

Jun Jun: Tomashino Hitomi 

Ves Ves: Suzuki Miho 

Bloody Dracul Vampire: Ono Hikari 

Death Falcon Shiba/New Moon Astralte: Hosoda Aya 

Baron Gilles de Rezt: Kasahara Ryuji 

Elizabeth Bathory: Miyazawa Akiko 

Lu-Fei: Kawasaki Miki 

Mandrake: Yukimura Yoshiya 

Demon Lilito: Endo Ado 

Demon Lilimu: Ogino Izumi 

Lilith of Darkness: Matsuoka Miki

Here's the cast of the Winter 2001 'Transylvania no Mori Kaiteiban' musical
 
Tsukino Usagi/SailorMoon: Kanbe Miyuki 
 
Mizuno Ami/SailorMercury: Kawabe Chieko 
 
Hino Rei/SailorMars: Kanda Eri 
 
Kino Makoto/SailorJupiter: Hayashi Yuriko 
 
Aino Minako/SailorVenus: Murata Ayumi 
 
Tenoh Haruka/SailorUranus:Takagi Nao 
 
Kaioh Michiru/SailorNeptune: Asami Yuhka 
 
Meioh Setsuna/SailorPluto: Hosaka Yuhko 
 
Tomoe Hotaru/SailorSaturn: Tomioka Mario 
 
Chiba Mamoru/Tuxedo Kamen:
                           Hidemasa Edo 
 
Chibi-Usa/SailorChibiMoon: Takabatake Kasumi  
 
Cere Cere: Honma Risa 
 
Pala Pala: Saeki Seira 
 
Jun Jun: Ajima Niki  
 
Ves Ves: Suzuki Miho 
 
Bloody Dracul Vampire: Ono Hikari 
 
Death Falcon Shiba/New Moon Astralte: Hosoda Aya 
 
Baron Gilles de Rezt: Miyauchi Yutaka 
 
Lu-Fei: Kawasaki Miki 
 
Mandrake: Yukimura Yoshiya