Characters die in anime right? Well, Sailormoon Sailor Stars is no exception. Here you will find a list of the main characters who do end up ending the life of another and their victims.
Sailor Galaxia
Mamoru
He was killed in technically episode 173, though we don't really find out that he really died until the end. He was aboard the plane when he was brought to Galaxia's dimension. He was really no match for her, though he did attempt to attack her with a cane.
Sailor Iron Mouse
She made the mistake of failing Galaxia too many times, and then hanging up the phone on her. A very, very bad move. She had figured out Sailor Star Fighter's identity though, which does make her good for something. She tried to get out of being killed by asking Galaxia a riddle, but lost her bracelets anyway. She died in episode 181.
Sailor Aluminum Seiren
She was killed after repeated failures and Nyanko pushing Galaxia to do away with the other member of the Sailor Animamates. She had actually figured out that Sailormoon had a "true star seed" but failed in her missions too many times and was unable to retrieve it. She was killed in episode 188. Galaxia took her bracelets.
Sailor Tin Nyanko
She was also killed for her failures, but actually she died after she was turned partly good by Eternal Sailormoon. She was missing one bracelet and was going to attack Galaxia in her confused state. Galaxia ended her life in episode 195 by taking her other bracelet.
Princess Kakyuu
She also died in the same episode as Nyanko. She put up a barrier to protect the other Sailor Soldiers and told them to get away. Her barrier was not strong enough against the golden queen, who kept on blasting until her attacks broke through.
Sailor Venus, Sailor Mercury, Sailor Mars, Sailor Jupiter
All four were killed in episode 196 when Galaxia tried to blast the Sailor Starlights. They jumped in the way taking the attack for them, and then Galaxia gave a finishing blast to take their Star Seeds.
Sailor Uranus, Sailor Neptune
They were both killed in episode 198 after they betrayed Galaxia and tried to blast her with the bracelets. Previously they had willingly joined her side and did away with Sailor Pluto and Sailor Saturn.
Sailor ChibiChibi
In episode 200 ChibiChibi turned herself into a sword for Sailormoon to fight Galaxia with. Sailormoon refused to fight her and thus Galaxia brought down her sword shattering Sailormoon's and killing ChibiChibi in the process.
Sailor Tin Nyanko
Sailor Lead Crow
Tin Nyanko had been fighting with Lead Crow for the capturing of a true star seed. When Nyanko discovered that Crow had actually found one she was there to betray her all the way. Just when Lead Crow was about to get Sailormoon's star seed, she was blasted and sucked into a black hole, where she died in episode 193.
Sailor Uranus and Sailor Neptune
Sailor Saturn, Sailor Pluto
They were both killed by their friends in episode 197. Uranus and Neptune choose to join sides with Galaxia and adorned the golden bracelets. Pluto and Saturn refused to fight their friends and allowed themselves to be killed.