Usagi is too nice (anime 90), she is not really formidable, since she always seeks to purify people instead of killing them.
I don’t like how passive Usagi is in the 90s anime.
That's actually a misconception, Usagi in the 90's anime was willing to kill people if she had too, her seeking to purify her human/looking foes rarely happens.
Dark Kingdom
Jadeite got ran over plane because of her and the team(he survived but they don't know that)
Nephrite killed due to infighting but his soul was redeem by Naru love for him.
Zoisite killed by Beryl.
Kunzite she tried to purify him didn't work, had to kill him
Beryl same as Kunzite.
Black Moon Clan
Koan was purify by Sailor Moon but only because Sailor Mars ask her too.
Berthier was purify because Koan ask Usagi to do so.
Calaveras and Petz ask Usagi to purify them after Rubeus almost killed them.
Rubeus who the Scouts left him to died on his ship. (which he did)
Saphir... purify himself before dying to Wisemen.
Prince Demande was convince by Usagi that Wiseman and he dies protecting her.
Death Busters
Kaolinite (the first time) was killed by both Inner and Outer Scouts.
Eudial killed due to infighting but...
Usagi didn't bother talking to her.
Mimete trapped forever due to infighting.
Tellu killed by Tuxedo Mask.
Viluy dies because her nanobots ate her alive because of Sailor Moon attack.
Cyprine and Ptilol were killed by Sailor Jupiter and Sailor Mercury.
Dead Moon Circus
The Amazon Trio died after restoring Usagi Dream Mirror but they gain Dream Mirrors themselves and their souls are taken to land of Elysion by Helios/Pegasus and he promises that one day they will be reborn as the humans they wish to be, with their beautiful dreams intact.
The Amazon Quartet convince by Usagi to give up being villains after Zirconia almost kills them.
Queen Nehelenia is ultimately redeemed by the Sailor Guardians' forgiveness, and reborn as a small child. Signs point to her having learned her lesson, as she is seen making an effort to become close to her subjects as true friends.
ShadowGalactica
Sailor Iron Mouse killed by Galaxia.
Sailor Aluminum Seiren killed by Galaxia.
Sailor Lead Crow killed by Tin Nyanko.
Sailor Tin Nyanko killed by Galaxia
Sailor Galaxia was saved by Usagi when she purges Chaos from her body.