The worst vs content I've ever seen was an attempted analysis on who would between these two characters. The video was made by people who clearly wanted Batman to win and had basically no knowledge of Mamoru spending the entire time insulting Mamoru and praising Bruce, having both act out of character and using arguments that showed they had poor knowledge of Sailor Moon, ironically poor arguments for Batman (actually claimed he was peak human), and poor understanding of vs debating in general.
Thing is, Mamoru is in a very different cosmic "weight class" then Bruce is. Batman is in DC's "street levels" while Mamoru along with the Senshi are cosmic defenders. Statwise this was never gonna be a fair fight. But what if that was changed? What if Mamoru and Bruce got into a fight but stats were equalized? The two do have some similarities in concept for sure. Sailor Moon and DC Comics are, at the moment, my two favorite series of all time and I think I have the ability to answer this.
For this battle I'm going to be talking 2 hypothetical battles between Batman and Tuxedo Kamen. Both will be in-character and will fight in a neutral environment with no outside help permitted. Batman's attack potency, durability, and speed will be amped to be equal to Tuxedo Kamen's. I choose to amp Batman's here rather then deduce Mamoru's because it's a lot more plausible to imagine a scenario where that would happen. Batman has gained superpowers temporarily on numerous occassions and has technology that could hypothetically enhance his stats. Meanwhile Mamoru's powers are derived from his Star Seed, the Golden Crystal, and as such it would be extremely difficult to lower his power level without outright killing him.
This will be seperated into 2 scenarios. In the first we'll be talking about a "standard" version of both. A Rebirth-era Batman with standard equipment vs. a Stars-Arc Tuxedo Kamen with the Golden Crystal unlocked. In the second I'll talk about the stronger version of them often talked about; a Batman with 1 day prep and access to all his equipment vs King Endymion, Tuxedo Kamen's future self with access to the lambda power.
While attack potency, durability, and speed are all equalized; there are other stats that can be compared.
Intelligence:
Mamoru's intelligence is highly advanced for a normal human. As a high schooler he went to a school with a 90 point differential
This explains further but a point differential is Japan's national system for assessing a school's difficulty and rank, with the highest real world number being 78. A 90 point differential is consequently a level that would be understood as beyond any real world school and suggest Mamoru's intelligence would be at the very least near peak for his age. Mamoru got accepted into Harvard, the arguably most prestigious college in the world on scholarship, despite it being a foreign school
and Mamoru can apply this level of knowledge practically. Mamoru and Minako are regularly treated as the most tactically savy of the good guys
Mamoru was able to use basically crowd-sourcing in the 90s, a principle first coined in 2005 in the real world, to use the human populace to help search the Silver Crystal outcompeting the Sailor Senshi and the Dark Kingdom, an entire civilization of people in the search for the Silver Crystal
Outthinking basically the entire Dark Kingdom hierarchy again goes to suggest his intelligence may be nearing peak human or beyond. He's also treated as similar to Sailor Uranus and Sailor Neptune who were able to decieve Viluy, a Type 1 Intellect who could created advanced holograms and nanobots that can tear people apart
and has an intelligence hundreds of times that of a human
All of this suggests Mamoru would be an intelligence at least nearing peak human, possibly superhuman. However all of this is absolutely nothing compared to Batman's intelligence.
In a world that is full of supergenius intellects, Batman is confirmed to be one of the two smartest people on the planet along with Lex Luthor
As part of his training Batman learned every course and every field, every subject and every trade, reading every book
Batman's knowledge is considered perfect with the sole exception of popular culture. That said, He has watched a Japanese anime series called "Sailor Moon."
Batman just from scaling would scale to type 5 intelligence feats. He has proven smarter then Superman and Darkseid
Superman able to recreate the Miracle Machine, a Type 5 technology able to warp the infinite multiverse on a metafictional level to bring about a "happy ending" to defeat Mandrakk
Darkseid being a conceptual multiversal deity who was able to create a device capable of turning people into infinite cosmic forces
Batman was also able to accurately predict when and where a time traveling robot would attack, something Brainiac 5 couldn't do
Brainiac 5 being a 12th level intellect that is stated to be one of Creation's keenest intellects
and could somewhat rival the intellect of Post-Crisis Vril Dox, a brain 1,000x stronger then even Superman's brain
Not inconsistent as Batman has been shown to rival Lex who equaled this version of Brainiac.
Obviously in this stat, Batman is cosmically higher then Tuxedo Kamen. Even as King Endymion where Mamoru has access to the intelligence of the Mercury Crystal and would be considered a Type 1 intelligence, Batman is cosmically smarter. Even the smartest entities in the Sailor Moon cosmology are Type 3 intellects like Saphir while Batman is a Type 5 intelligence.
Skill:
I divided skill previously into tiers such that F Tier is superhumanly unskilled, D Tier is unskilled, C Tier is proficient, B Tier is master, A Tier is superhumanly skilled, and S Tier is transcendent.
Most SM fighters don't really have much skill feats, as Sailor Moon fights are primarily battles of magical power and techniques (haxes.) Mamoru has a bit more skill then most in the verse, showing basic proficiency with cane and sword
as Prince Endymion he was prince of the Earth during a techology level similar to the middle ages, and so would likely have been taught some level of formal sword fighting. He also displays notable dexterity during the first arc. Overall he definitely seems consistently C tier in terms of skill.
Similar to intelligence, Batman massively eclipses Tuxedo Kamen in skill. Batman has long been noted consistently as the master of all martial arts
which he combined into his unique martial arts style
This alone would qualify for low A tier skill but Batman has skill feats beyond this.
Batman's martial arts allow him to disable foes cosmically stronger then him like Solomon Grundy
Batman's skill arguably has progressed to the S Tier, he was able to win in a mystical mental plane fight via martial arts training
He's also able to spar with Wonder Woman
Wonder Woman regularly fighting the god Ares, the concept of warfare and tactics, who is omnipresent at every battle across time
While Ares is stronger then Wonder Woman, this is more due to his raw power rather then being any more skilled then her.
Bruce is obviously massively more skilled then Mamoru or indeed anyone in the Sailor Moon universe. Even as King Endymion where Mamoru has 1,000 years of experience, even if you assume it was all combat experience, it would only really be on the level of Batman's feat of mastering every martial art.
Range:
In contrast to the prior categories, this one is cosmically in favor of Mamoru.
Batman is one of the top 10 shots alive
and is able to make a shot Deathstroke describes as impossible even for a pro
That said his maximum range would generously be in the range of a few kilometers, similar to the maxium known range for snipers in the real world (with the absolute farthest recorded being 3.54 kilometers away.)
Even in the first arc, Sailor Senshi's attacks were able to destroy dimensions stretching to the horizon
which would be a distance of 4.7 kilometers. The shine of Mamoru's golden crystal and Usagi's silver crystal created a light that shone across the universe.
Obviously this range is completely outside the range of what Batman can normally affect. Surprisingly this doesn't seem to change even in the second scenario. While Batman's range does grow to the cosmic level he doesn't seem to have much with universal AoE save for a Mother Box.
Stamina:
Stamina can be kind of hard to directly compare and as a result it's not a very clear cut thing who has more stamina.
Mamoru used his lifeforce to stabilize Chibiusa's life after her soul and star seed were taken from her body, something Luna states will place a huge strain on his body
Despite doing this for an extended period of time, Mamoru aids the Guardian Senshi against Mistress 9
Mamoru shows no exertion despite such effort causing the Guardian Senshi to collapse
After unlocking the Golden Crystal, it is possible Mamoru has infinite stamina as the Golden Crystal shares power with the Silver Crystal
which is constantly stated to have infinite unending power
Batman has many feats of stamina, but I believe by far his greatest one is Rebirth fighting against an unending horde of demonic monsters for 39 years in another dimension
Assuming you think Mamoru's Golden Crystal really does give him infinite stamina, then the two are definitely never going to tire each other out in a fight.
So now I'm going to over their unique powers for scenario 1 as well as any possible counters the other side has for it, starting with Mamoru as he has less abilities to talk about overall here.
Tuxedo Kamen's Abilities-Scenario 1:
Mamoru has the ability to project an energy attack from his hands called "Tuxedo La Smoking Bomber"
as well as general Sailor Moon verse energy projection.
Batman's standard batsuit absorbs energy and projects it back as electricity
Speaking of electricity, Mamoru can use his psychometry to shock someone
Batman's suit is electricity proof and he can redirect it to those around him
Mamoru has the odd flight/levitation think SM characters do where they will hover around, usually in energy orbs, Mamoru doesn't seem to use one though
Batman obviously has a bunch of experience fighting flying opponents, that said given Mamoru's range this is definitly a notable advantage.
Mamoru has displayed mild stealth abilities, complimenting his background as someone who broke into jewel stores attempting to find the Silver Crystal
Batman has numerous counters to this, not least of which being his natural insanely strong senses
Mamoru can heal wounds casually, even bad bloody wounds to be nonexistent
Batman can't really negate healing abilities with standard equipment. As such he would struggle to wear down Mamoru unless he uses an incapitating form of attack.
Mamoru's future self who watches people through time
can send information and power to his younger self
This would give Mamoru perfect information the entire time, something that would be highly difficult for Bruce to fight.
Mamoru possesses mild telepathic abilities that usually manifests as prophetic dreams. Mamoru is able to sense danger to himself and his loved ones
and likely has the same ability of the Senshi to sense the general intent of a person, a mild form of mind-reading
Batman would be very easily able to resist this as due to his immense willpower and training his brain is almost immune to telepathic attack able to make his thoughts chaotic so a mind-reader couldn't read them
and even able to resist the psychic power of the Spectre
Mamoru has the power of "Henshin" or transformation
Henshin allows for teleportation across dimensions, and the ability to teleport others through dimensions
Batman doesn't particularly have a counter to dimensional BFR other then the fact that Mamoru has to get into close range to teleport others. While Batman does have a JLA teleporter that can teleport him from anywhere in the world to the Watchtower
This would only help if Mamoru tried to BFR Bruce to somewhere else on Earth, and if he tried to BFR him to somewhere in another dimension the Watchtower teleporter range probably isn't long enough to reach.
The Henshin power can not only give off energy but also a blinding light
This is unlikely to do anything of note to Batman who has many times shown the ability to fight blindfolded
Batman's Powers-Scenario 1:
Batman has a far greater amount of abilities. This is to go over the greatest of his standard options and what if anything Mamoru can do to counter.
Batman's strongest weapon usually is his stealth, so incredibly strong that he can disappear even from the perception of Superman
or indeed Superman and the entire Justice League
Superman being a character whose senses have reached into other dimensions before.
That said Mamoru has perhaps the hardest counter to this ability one can imagine. Mamoru's psychometry allows him to sense all people on Earth, including individuals and their current condition:
giving Mamoru constant awareness of Batman's current location. He can also literally be told where Bruce is currently by his future self, as King Endymion can give information and power from the future as mentioned earlier.
Batman's martial arts training not just increased his skill, it also gave him several more hax techniques.
Batman knows every single nerve strike in the world
which functions as a form of hax that allows him to induce pain in far stronger enemies like Wonder Woman or Solomon Grundy
stop an enemy from breathing
and erase memories
Mamoru may able to resist or endure most of these effects. His Golden Crystal is explictly an equal to the Silver Crystal which allowed Usagi to recover her memories in the river of Oblivion
He was able to endure the pain shared when Usagi had her star seed removed from her, showing a level of pain resistance
and doesn't need to breath. While nerve strikes from Batman might be effective against Tuxedo Kamen I don't think they would be a one-shot.
Through the martial arts technique of Thorgal, Batman is capable of learning the future
Possibly helpful but Mamoru already has similar to greater being able to get information from his future self.
Batman has learned to sense magic's presence
This would likely inform him of Mamoru's presence and power source, if he didn't already know that.
Batman is trained in hypnosis
However Mamoru has cosmic resistance to mind hax, unaffected when Metaria brainwashed the populace of humanity.
Batman has learned the limited usage of backwards magic, possibly his teacher Zatara who taught him escape artistry
However his level of proficiency is unknown and from Zachary Zatara we know that it takes high levels of skill in backwards magic to affect humans like Mamoru. Batman also learned from Zatanna a charm to prevent the usage of magic for an hour for even a magic user like Circe
This may seem to be an auto-win for Bruce however the Golden Crystal uses the same power as the Silver Crystal which when developed enough can resist even the power nullification of the planet Nemesis which nullifies powers including magic
Beyond his developed abilities, Batman has also built many pieces of advanced technology even for standard missions. Some of the stronger examples listed.
Batman has a variety of binding weapons including a rope strong enough to bind a powerful dragon's mouth shut
These are unlikely to work on Mamoru who can use the magic of henshin to teleport away.
Flashbangs powerful enough to blind the Spectre or Superman taking advantage of their enhanced sight
This would not be super helpful against Mamoru who can simply be directed by the spirit of King Endymion
Batman has various knockout gas grenades, tranquilizers and toxins to induce a deathlike state temporarily
However Mamoru was able to go to Crystal Tokyo and was unaffected the poisonous mist that enveloped the city
Batman could use liquid nitrogen capsules that can freeze people
This might work however King Endymion might be able to free his younger self and Kunzite was able to freeze a city but did not even try this tactic against the Senshi.
Batman has a lot of gadgets and abilities but these are some of the most relevant. I should note that technically Mamoru has a weakness that could be exploited that he is connected to the Earth and should massive damage befall it, Mamoru will fall deathly ill but this is obviously not something Batman would exploit as he is a Hero and would not do massive damage to the Earth, even assuming he had the AoE to do so, to win a fight.
Fight-Scenario 1:
The Sailor Moon characters appear in the DC Universe and on the surface things are good with Usagi spreading prosperity and love. Batman, being himself, begins to develop a contingency to use against Usagi if need arrives as he does to everyone in the JLA, a device capable of nullifying the Silver Crystal.
Mamoru hears of this and not wanting a device to exist that could potentially kill his love takes up his old jewel thief persona and goes to Gotham to nab the device. Bruce hearing that Mamoru is in Gotham looking for him takes a temporary supplement to boost his powers to Tuxedo Mask's powers and goes to confront him. How does this go?
So the most immediatly noticable thing about this fight is that it is a fight with perfect knowledge on both sides. By perfect knowledge I mean both know every single action that can and will happen afterwards due to Bruce's cosmically higher intelligence and skill and Mamoru literally being told what will happen by his future self. This means that the immediate problem for both is that neither can make a mistake, and that getting either in a losing position is fundamentally impossible if there is any way out.
This is a problem as with stats equalized neither have any real way to get an easy win. Batman can do damage to Mamoru sure if Mamoru gets close but Mamoru can simply heal himself with his own powers, let alone just keep out of range via flight and teleportation as well as exploiting his far superior range.
Bruce can't particularly stealth around Mamoru but he can take cover or get away from essentially every attack Tuxedo Kamen can do via his manueverability from skill and things like grappling hook.
In terms of win conditions Tuxedo Kamen's best wincon is teleporting Bruce into another dimension, although he wouldn't know what Batman can return from as Batman does have some teleportation with JLA transporter which Mamoru wouldn't know the limits of. Bruce's wincons are more speculative; it's possible something like backwards magic, freezing, or the bodily manipulation of his martial arts could effect Mamoru although none are very surefire. However there's another advantage Bruce has; Bruce has prior knowledge of Mamoru.
Bruce has knowledge of the series of Sailor Moon and because he can sense magic he would immediatly know Mamoru is manga Mamoru instead of anime Mamoru whose powers come from the power of love and physical training. It's very likely he would be able to logic out the best attack pattern and manipulate Mamoru, possibly by appealing to Mamoru's sense of honor and chivalric combat.
You may wonder why King Endymion wouldn't just tell his younger self about Batman. Well Batman's intelligence advantage is so great I believe he could trick both Mamoru and King Endymion at the same time! He has outhought Brainiac 5, the Brainiac of the future before.
So this leads into the question of which is more relevant here; having a more clear wincon, or having information on your opponent and the ability to manipulate them and that I think really depends on your view of how viable any of Bruce's win conditions are against Mamoru. Personally I favor Bruce to win via outwitting Mamoru somehow here given the sheer breadth of his abilities but I understand if you disagree. In particular I think he might be able to engage Mamoru in a mental plane battle of pure skill via his skill feat which he would win due to raw skill though if you think that brainwashing resistance protects from that, that's fine.
Scenario 2:
What changes in scenario 2? Well a lot. In scenario 2 Mamoru has the Lambda Power, the power of all the Senshi's abilities
as regenerates one even if one is completely erased in the Galaxy Cauldron
some of the Senshi powers that King Endymion have access to include star seed stealing/existence erasure:
releasing the silence which wipes all life
Temporal BFR:
The ability to absorb people into the Golden Crystal or seal them away
Duplication across time
and many more magical abilities.
With prep time Batman has a whole bunch of insane technology stored away including a dagger with a fraction of the power of the wizard Shazam
Platinum Kryptonite that can give one the powers of a Rebirth Kryptonian
technology that can negate regeneration, even the regeneration of Swamp Thing
A Mother Box and a Lightning Rod that can siphon the Speedforce
Robot Duplicates of the Justice League
and the Helm of Nabu (although from what we know Nabu has not chosen Bruce so he can't access the full magic of Dr. Fate)
as well as a whole bunch more.
This fight is so different as to almost be a different fight as the two's battles would now extend throughout the universe and be filled with cosmic powers and reality warping abilities. Batman has access to a Kryptonian's resistance which should be helpful against the many types of offensive haxes Endymion has. Even still this is going to be a hard fight for either.
In some ways this is like the hypothetical fight of Sailor Moon vs Superman I've talked about before as Batman can essentially give himself Superman's powers while Mamoru shares many of Usagi's powers. That said Batman has a few crucial advantages in that department.
In particular Batman does have a way around the Lambda Regen as he was able to defeat the even stronger regen of Swamp Thing. He can get around the range difference via the mother box and the raw power difference just isn't here. Combined with his prior knowledge on Endymion this may sound like it should go clearly to him but I think it's a bit more complex because Endymion can just as easily counter anything Batman can do.
Temporal Duplication and automatic teleportation can keep Endymion safe from speedforce type blitzing or mental manipulation. Mamoru has his own reality warping coming from the Silver Crystal to defend against something like the Mother Box's. Sailor Teleport can counter dimensional bfr and so on.
Really this is a fight where both sides have essentially perfect knowledge and ability to counter each other. However I would probably side with Endymion for two crucial reasons; pretty much all of Batman's abilities outside the Kryptonian ones in this scenario comes from technology which can be disabled or telekinetically removed or energy drained while Mamoru's power comes from the Lambda Power channeled through his Golden Crystal, and Mamoru's abilities are magic which may be able to circumnavigate the Kryptonian resistance. Beyond that Endymion just has more experience fighting at this level of power and with his age is a more cautious wise and less headstrong individual that is far less prone to manipulation. Unless Nabu agrees to give Bruce the powers of Dr. Fate, I don't think he would win here.
To me there's something oddly fitting about this. Batman won the scenario where both were limited to a more street level type arsenal, which is his domain but Tuxedo Kamen won the more cosmic type battle where both had far greater powers and arsenals. Bruce and Mamoru are both highly admirable characters representing the role of man in a world of aliens, wizards, and gods. However Tuxedo Kamen represents man's union with the divine, his love with Serenity being the love between Heaven and Earth while Batman represent man standing alongside gods distinctly via his ambition and will, not being at one with them but instead proving one's worth even when wholly mundane oneself. In this way it makes sense to me that Bruce would win an Earthly battle in a city street late at night and Mamoru would win a Heavenly battle through the night stars.
