Sailor Cosmos... where do I begin? We aren't entirely sure who exactly she is. She's supposed to be the ultimate from of Sailor Moon, and the future she speaks of is long after Crystal Tokyo. In this future, we can assume that basically everyone is dead, and it's just Cosmos and Chaos going at it. Now as to who she is, as a person, some think it's NQS, some (like myself) believe she's an incarnation of Sailor Moon after the end of Crystal Tokyo, still others sy that it might be the orignal Queen Serenity. And her role, as her name would imply, is that she's some kind of universal Senshi to protect the whole universe. So that is Sailor Cosmos

I explored the theory of her being the original Queen Serenity in another thread.

It makes the most sense to me.

HEY SO I THOUGHT OF SOMETHING TODAY AND IT KINDA BLEW MY MIND. SORTA. MIGHT NOT BLOW YOUR GUYESES. ANYWAY...
So, in the Headcanons thread, quite a while back, someone (I believe it was Mayonaise) said that Usagi was always intended to be Sailor Cosmos. So that kinda got me thinking...
So, a lot of people think that Queen Serenity was not originally from the Moon (I believe this is probably true). I have this idea that QS was, in fact the ORIGINAL Sailor Cosmos (or the person who would become her if the universe ever needed it, which leads to the idea that Cosmos only awakens if Chaos does). But when Queen Serenity left wherever she was from and formed the Moon Kingdom and all that jazz, the Ginzuishou somewhat attached itself to the Moon, and became its sailor crystal, because that was Queen Serenity's star seed.
BUT, when Queen Serenity died sending everyone into the future, Princess Serenity/Usagi received the Silver Crystal, and she became Sailor Moon, but, at the same time, she still had the ability to become Sailor Cosmos if the need ever arose. So yeah, maybe once Queen Serenity was Sailor Cosmos, but the one we know might be NQS or another incarnation.

That is kinda similar to a theory a friend told me they had (they may have posted here as they used to be a GC member) that Queen Serenity and Usagi/Sailor Moon/NQS are like reincarnations or carry the spirit or something like that of Cosmos. So I think your theory would fit in that.

I think she is the true form of Sailor Moon before she becomes Neo-Queen Serenity.

So a friend and I were discussing Sailor Cosmos on skype a few weeks back and I wanted to add our discussions here.

SKYPE SHENANIGANS wrote:

Mah friend: Yeah, she's her antithesis.
Mah friend: But irony is that she also isn't even close. Because Usagi is actually the antithesis to Chaos.
Mah friend: Which makes it sad. Since Galaxia is used and then destroyed by Chaos.

yuniecorn ᕕ( ᐛ )ᕗ: I kind of agree and disagree. As I would say more specifically Sailor Cosmos is because like how Metellia, Wiseman, etc. we're all seen as incarnations of Chaos and Sailor Chaos is the strongest form of Chaos, I see all the wielders of the Silver Crystal as incarnations of Cosmos, with Sailor Cosmos being the final and strongest form.
yuniecorn ᕕ( ᐛ )ᕗ: if that makes sense. i've been reading too many theories lmao

Mah friend: Hmmm, see I agree with it being Sailor Cosmos, but more the Cosmos that Usagi will become. Not the one we met. Because she was not the one who was able to fight that battle.
Mah friend: She even says that right now she's not the true Sailor Cosmos.

yuniecorn ᕕ( ᐛ )ᕗ: Oh I definitely agree.

Mah friend: Chaos sent multiple incarnations of itself out specifically to obtain the silver crystal. Because Usagi is the light to its darkness. The most beautiful shining star. So by default her existence meant that they'd always be attacked. So in that timeline Usagi is most definitely the antithesis to Chaos. Now in the future Cosmos comes from, she fled from the battle with chaos after the stakes became too high. Which if you believe Cosmos is Usagi, you have to imagine what it would take to break her in such a manner.
Mah friend: But then there's also the fact that present day Usagi has lived a different life than Cosmos and NQS.
Mah friend: So she might be stronger willed by default.
Mah friend: I used to ponder on if Cosmos was simply a title given to the warrior who shone the brightest and stood up to darkness per timeline.
Mah friend: So in one timeline it might be someone else than in another.
Mah friend: I try not to rely on the design too much since Naoko was notoriously lazy sometimes with changing the designs of certain characters. lol Then the fact that Naoko claims to not know who Cosmos is either.
Mah friend: sorry bb grjhjr I get excited

yuniecorn ᕕ( ᐛ )ᕗ: NO IT'S FINE. i like talking about this. I just have to make sure I form my thoughts together ;v;

Mah friend: I actually got so excited I got out of bed haha. I can't properly type on my phone. My nails get in the way.
Mah friend: lmao I forgot Shampoo calls Akane "Pervert Girl".

yuniecorn ᕕ( ᐛ )ᕗ: I don't know...it's all very 'up in the air'. I personally like to think that Cosmos is a) either a possible reincarnation of Usagi who died which would be a callback to how 'Usage's light will never die'. She just gets reincarnated again, however, this form wasn't able to grow up in peace, with friends, her lover, etc. therefore wasn't able to become as mentally strong as Usagi. It would explain why Sailor Cosmos remembered being at the Galaxy Cauldron since reincarnations can remember at least some parts of their past lives (Ex. Usagi eventually remembering her past as Serenity) and why she refers to Usagi as 'myself' since that technically is who she once was. Option B) is that I think that throughout the series we constantly see there has to be a balance between dark and light. Like I said earlier, the villains are the incarnations of dark (chaos) while I believe that Usagi, Chibiusa, Queen Serenity, etc. are incarnations of light (cosmos) and some of them are obviously purer than others and can achieve the ultimate form of Sailor Cosmos. I hadn't thought of Sailor Cosmos working as a title similar to how Sailor Moon is a title for Usagi/Chibiusa but that does makes a lot sense. I think that there could be more than one Sailor Cosmos, however, it would be an extremely rare form to achieve. I also like the theory that Sailor Cosmos could be just a physical form of the silver crystal too. shrughs
yuniecorn ᕕ( ᐛ )ᕗ: OKAY I'M DONE
Mah friend: ISN'T IT AMAZING HOW MUCH ONE TITLE/CHARACTER CAN INVOKE SUCH THOUGHT?

yuniecorn ᕕ( ᐛ )ᕗ: YES

I really like the reincarnation theory, which I haven't considered before. I used to think she's just a future form of Sailor Moon but not Usagi (a descendant from her line). But I think I like the reincarnation theory better.

I think she's a reincarnation too. The manga already explained she is a future Sailor Moon/Usagi. I say Usagi because the manga literally added the picture for reference in Sailor Cosmos explanation.

I think reincarnation because it just seems better to me than thinking Neo Queen Serenity suddenly gaining the power to transform again.

Although I read a fanfiction where Neo Queen Serenity literally assimilated with the crystal and when she became cosmos, it was as some have said here.since the crystal doesn't exist, as Cosmos she uses all star seeds

If she's a reincarnation like Usagi is, she has a lot of her past memories which would explain why she said what she did in the manga.

I feel like she is a reincarnation. I mean think about it, as Usagi, almost everyone still sees her as Princess Serenity- they bow to her from time to time, referring to her as Princess, she's basically just living on as another alias, but still is Princess Serenity. I think this works for Sailor Cosmos, since she even said at one point at the manga that she knew her other self was sad and lonely during that time, so she decided to accompany her and show her the way. Also, there was a hint that Cosmos has returned to the same timeline again and again because she says she remembered the action she took, where instead of destroying the cordon she prevent chaos from taking over instead. 

It's safe to say that Cosmos is most likely a reincarnated Serenity. Let's think about it, Serenity didn't have Senshi powers- reincarnated as Usagi and she gets it. NQS didn't have senshi powers - so reincarnated as Cosmos and she gets it back. I guess it's this royal bloodline concept where the royal blood is stronger than other powers, so basically when one assumes a position of royalty, they lose their powers because their royal blood is stronger than that power. I don't know im just making theories up XD

I wonder if she is a reincarnation, what her new name would be and what her life would have been like leading up to her fight with Sailor Chaos.


She's had the names Serenity and Usagi Tsukino. They both are so different but they fit. 


I wonder if she would have another fitting name or something completely different and she looked completely different.


I'm in the camp that Usagi is not the same as Princess Serenity but that Usagi is Neo Queen Serenity because of different and same lifeline.


I wonder if a story was ever made where we get introduced to this character and she suddenly gets a flash of a distant memory from an old life and takes off during the fight with chaos after realising she has another way of destroying her and that's when we are reminded suddenly that this new character is a new life of Usagi.


It's made clear Usagi as Eternal Sailor Moon is stronger than Sailor Cosmos and a lot of this has to do with her emotions, like hope and stuff.


It makes me wonder what kind of person Sailor Cosmos cilvilian form is and how she lived...

I firmly believe Cosmos is the future form of Moon.... after her tenure as Queen and Sovereign. 
We're all aware Usagi's guardian powers ceased when she becaome Queen. And why... because the world was a peace (save for the Black Moon Clan incident) the citizens were happy with their extended lifespan etc.

Obviously much further into that future things weren't so rosy. 
Keeping in mind that the Crystal does NOT grant immortality Endymion and the senshi by this point may no longer be around.
(I could be wrong... but as a direct descendant of the Moon her lifespan is longer than the others)

With the whole universe in peril she obviously needs to help ChibUsa and her guardians.. but seeing now as ChibiUsa is likely basically Sailor Moon, and with the power Usagi has/had as Queen she's leveled up to the highest extent. But alas going by the way she spoke in the manga she likely watched ChibiUsa perish and thus being the catalyst for her going back to the past to try and fix this. 

I haven't read the manga for goodness knows how long, so it's likely I've missed something.

I also agree with the theory that Cosmos is the future form of Sailor Moon. Either from a different timeline / an alternate Universe or from the same one, just a long time after the 30th Century. The problem is, that we don't know which concept of time travel Takeuchi uses for the Sailor Moon Universe. On the one hand there is the 2nd arc, in which the same persons can't be near to each other for too long, which hints towards the 1 universe time travel concept rather than a Multiverse. On the other hand there a the later Arcs and the "The future is not written in stone" concept, which more or less hints towards a Multiverse. But I think Takeuchi used this, to keep the Arcs interesting, because we already saw the distant future in the 2nd Arc so how could Sailor Moon possibly lose?
So all in all I think the Sailor Moon Universe uses Multiverses for time travel, and Neo Queen Serenity is from a different timeline, rather than the exact future version of the main Usagi. The "the same persons cant be near each other" contradicts this, but I think Takeuchi just forgot about that and began using the Multiverse concept, to keep things interesting.

 But I think the whole "Which form of time travel is used in Sailor Moon" could make a whole other topic xD

Back to topic:

If the Sailor Moon Universe uses the Multiverse time travel, Sailor Cosmos could be Sailor Moon but not Neo Queen Serenity, because the events in her timeline played out differently: Sailor Chaos awakened and she had to fight her, instead of becoming Neo Queen Serenity and ruling an peaceful earth. In that case Chibi Chibi and Sailor Moon being together does not create any problems, because even though both are Sailor Moon they are not the same person. This would imply that in Neo Queen Serenity's timeline, the events from Infinity, Dreams and Stars never happened, which would explain why most of the outer Senshis except for Pluto are absent: they weren't needed and thus never awakened.

Poking a million other topics shows a way Cosmos can be Sailor Moon from the future, without contradicting with Neo Queen Serenity and giving up / losing her power.

But even if the Sailor Moon Universe uses one timeline, I think it is possible for Cosmos to be the future version of Sailor Moon / Neo Queen Serenity. It is never exactly stated why Neo Queen Serenity lost her powers. "With the 20th Century began an era of peace." It is plausible that she lost her powers, simply because she did not need them when there were no threats to the Silver Millenium. With every new enemy Sailor Moon got new powers and as Sailor Chaos rose, Neo Queen Serenity's powers awakened once more and she turned into Sailor Cosmos and started fighting Sailor Chaos. The only thing speaking against this is, that Sailor Chibi Chibi and Sailor Moon can be together without problems, but maybe Sailor Cosmos changing her form plays a role in that too. But the most likely explanation is that Takeuchi just forgot about it.

But I feel like I'm digging way to deep into this topic. I could continue writing about this and possible hints for hours, but I think I'll keep more fore later!