I’ve been discussing Pluto a lot lately and I remembered this one moment in the S manga where Saturn asked Pluto to close the door behind her so she could do her duty and sacrifice herself. She was basically like “you HAVE to do this. You understand.” And Setsuna did. And once she did it, she freaked out and started crying and started yelling Saturn’s name.
Which I think leads to a clear parallel between Sets and Saturn- they were both creatures of duty, and they were bound to do the jobs NOBODY else would want to do. They led shitty, lonely lives because of it. The difference is of course, Setsuna eventually got sick of it, defied her duty and died. Saturn never did- but her arc was mostly about getting people to understand that her duty wasn’t evil- that death was the neccesarry thing that led to rebirth. She destroyed Sil Mil so the cycle of reincarnation could begin. In the same way, she had to put down her glaive on earth because that was the only power that could destroy Pharaoh 90- who had infected the earth at this point- and even if it meant harming the rest of the world, she trusted that as long as she held up her end- destroying the monster Usagi couldn’t destroy- Usagi would be able to ensure everything was reborn and the world was repaired. She was part of the process- she had to kill everything so Usagi could ensure rebirth. Just because it was a scary part of the process doesn’t mean it’s bad. Saturn was looked down upon for being a natural part of life.
After defying her duty to save the world, Setsuna was given a second chance at a not-lonely, not-shitty life, to have freedom the way she wanted. And after performing her duty to save the world (in defiance of the people who wanted to kill her), Hotaru was also given a second chance. And that’s why I think it was really fitting and significant that Setsuna was one of the people who immediately came forward to adopt Hotaru- they were both condemned to horrible lives, but despite that, they did the right thing and went all out for the people they loved. They knew what had to be done, and it went beyond what they were told was right. And because rebirth is such a theme in Sailor Moon, they were given a second chance and able to help each other build lives where they could live life how they chose- follow their duty on their own terms. It’s really important that these two ladies found each other, because they share the same pain, and now have the chance to help each other be reborn.
This parallel was basically entirely lost in the anime, since Sets was dead by the time Saturn came and her death was different and all that- though she did still enter a family with Hotaru and all that. I’d really love to see the connection between Sets and Hotaru explored more because there’s a lotta potential there.