WMG / Mystery Skulls Animated

The dog Mystery is a Kitsune.

It's been suggested as he grew six tails during the flashback when he tore off Arthur's possessed arm.

• Whether he's good or evil is up for debate from lack of evidence. On the one hand his mirror shattered, on the other he ripped off Arthur's possessed arm.
• Blue-and-Orange Morality? Fox spirits aren't exactly known for adhering to human standards of morality.
• If he is a kumiho, the hesitation of his character profile to divulge his favorite food takes on a very dark tone, since kumihos are in fact man-eaters. However, him being a kumiho would raise questions about his connection to Shiromori, who is clearly Japanese, while kumihos are Korean (while him being a Japanese kitsune would make perfect sense in that optic).
  • Though its entirely possible in universe they are two different names different cultures gave to the same creature
• Confirmed as of Hellbent. It's also suggested that he may have used to be evil, so him being a kumiho (or a mix of both) is still not entirely out of the picture.
• He's definitely a bakemono yōkai - since there's a mix of Japanese elements to the series, that's pretty much a given. What kind of a yōkai is still up for heavy debate. He seems to most resemble an imari kitsune - benevolent and extremely powerful Japanese guardian spirits in the Shinto religion. However, he also has some features of a yumo kitsune - a variety far wilder and often much more hostile toward humanity. As of Hellbent, his current chosen role for himself seems to be that of inari-kami for Vivi.

The cave where Arthur was possessed and Lewis became a ghost is an Eldritch Location that feeds on negative emotions.

Arthur obviously has no chill when Lewis, Mystery, and Vivi are chumming it up in the front seat and he's staring stormily out the window. Whether it's the potentially recent development of Vivi and Lewis's relationship, or some other situation that's bummed him out for which we have no context, he goes into the spooky cave feeling sour and ends up giving some ectoplasmic asshole a free ride because of it. The rest of the gang is safe from ghostly interference because they're all in good spirits (ha). Similarly, Lewis sees Arthur standing on the ledge and becomes enraged just before he dies, giving the cave's spooky magic leeway to bind his soul to Vivi.

There was a fourth member with a green theme who got in a fight with Lewis and broke his nose.

Vivi whom was pissed about it kicked her out, while not telling Arthur Lewis, or Mystery/Ben. Arthur and the green girl I will call Ivy had a relationship and when she was kicked out Arthur became angry and envious of what was taken away from him and that's why he became easy to possess and why he kills Lewis as he saw Lewis as the cause of his lonely existence.

• There is a significant hole in this. If Vivi did kick out a member of the group who was Arthur's girlfriend without him or the rest of the gang knowing then he would be more pissed off at her then Lewis in that specific case. Going behind someone's back in a case like this will cause serious issues for everyone....
  • No hole if Arthur secretly rather watch Vivi suffer if we don't do the theory of mindwipe.
    • I like the theory and we could go with Vivi being mind wiped so she won't suffer anymore.
• Well, Chloe certainly wants to be the fourth member and has a green theme. She also wants an undead boyfriend. Hmmmmmm.....

Mystery is Obfuscating Stupidity

From the mere act to tearing off Arthur's arm while it was possessed, its pretty clear Mystery is actually pretty damn powerful, at Animalistic Abomination levels. (as befitting a high level kitsune yokai.) In fact, if the group went on Scooby-Doo esque adventure similar to the original they're expies of, Mystery would probably transform and curb stomp any actual supernatural threats they faced off against, probably with a bit of Laser-Guided Amnesia in order to prevent his friends from finding out. The reason he doesn't attack Lewis' wraith, even when it was clear it was going to kill them, was because he knew the wraith was Lewis' restless soul, and he did not want to attack someone who was an actual friend of his.

• Either that or he only reveals his powers when someone is in extreme danger (if he had not torn off Arthur's arm off, he would likely have lost his soul to the entity possessing him), because he finds it more fun that way.
  • Mystery decided to follow Arthur and Lewis, as seen when the group was splitting up and he had his head turned towards those two. He must've known that something was going to happen. He later mind-wiped the others, seeing as neither recognized Lewis' ghost, and was the one who had a flashback. It's likely that he has been playing dumb so the others wouldn't have to deal with the pain of losing their boyfriend/killing their friend.

Arthur was easily possessed because he was feeling like he was being ignored by the entire group while they were all happy with the recent relationship development.

Of course Arthur would have to be good friends with the whole group if a group dynamic like this were to work. Arthur in the flashback isn't necessarily jealous of how Vivi and Lewis got together; in fact he is actually happy for them. His actual problem is that he feels left out by the entire group due to the relationship. Notice how Arthur was shoved in the back and all of his friends were in the front seats? Even without the ghost that possessed Arthur getting involved, ignoring or not addressing one member of a tight-knit group like that is very dangerous for a group dynamic. Arthur likely was very off put by this...thus making him easy to possess because he was upset about being ignored. It's very possible if Mystery didn't bite his arm off after he killed Lewis then the full possession would have taken place and Arthur would have to watch as the ghost uses his upset emotions to kill the rest of his friends.

• This may have some basis, given other pictures in "Freaking Out" and "Hellbent". In most images, it doesn't seem like Arthur is anywhere near as close as Lewis is with his family and Vivi, and in two of Lewis' flashback illustrations all of his and Vivi's attention were on each other—never on Arthur. Of course that's to be expected for two young adults in love, but his estrangement from the pair may play a very big role in the tragedy.
  • In addition to this, Arthur's Green-Eyed Monster form wasn't because he was jealous of Lewis' relationship with Vivi (or for the other reason as some fans like to believe), it's because Lewis took the role of driving the van. Notice how happy Arthur looked while taking the wheel, and compare that to his expression while looking at Lewis. The car also clearly belongs to Arthur, which would make his jealousy/envy more understandable.
• Adding to this, Lewis isn't actually envious of their relationship at all. The green entity simply represents envy and possessed Arthur the good ol' fashion way. Alternatively, Arthut is sad over being left out, and is actually envious of Lewis taking the wheel of his car. If he were really envious of the relationship then Vivi would've done the job just fine as well.
• Eventually it will be revealed that Arthur is actually only focusing on the negative aspects on their relationship. While he's not entirely an Unreliable Narrator the fact that the negatives outweighs the pros of their relationship is what's eating him up inside. In reality Lewis and Vivi just focus on each other when they're around and Arthur isn't willing to interrupt whatever they're doing (because they're couples and it's none of his business), but when they're actually together they pay full-attention to him. Human beings are programmed to focus more on the negative side of things, so eventually Arthur will realise that it's not as bad as he's making it out to be.

Arthur was in love with both Vivi and Lewis.

But due to self-esteem issues, which may or may not tie into the above WMG, Arthur refused to believe he could be part of something so perfect and the force that possessed him capitalized on his self-loathing.

Arthur was terrified of the adventures the group went on but suffered through it because of I Want My Beloved to Be Happy, which could have been platonic or romantic.

Vivi at the very least adores creepy and spooky stuff and nothing indicates Lewis didn't enjoy the adventures. Arthur's desire to see his friends happy was stronger than his fear but the fear kept growing and festering until it got him possessed and Lewis killed.

If Mystery Ben really is turning Mystery Skulls into an animated series, the actual Mystery Skulls band may want him to change the name of this new series.

But why would they want to do that? Maybe because they don't want their band to only be recognized only as a 4 minute YouTube video. Unless they approve.

• The video was officially endorsed by the band.

The next story will be about the gang trying to set up their own Gang of Four. But their plans are continuously messed up by the Supernatural.

Eventually, they all Rage Quit.

Mystery was.

• Was What?
  • This was probably supposed to read as "the one responsible for the events that led up to Lewis' death," a la The Dog Was the Mastermind, due to his suspicious placement and depiction at the time when Arthur was possessed and Lewis died, among other things. The problem is that just as many things point to him being helpful towards the Mystery Skulls rather than malicious.

Lewis is descended from Manolo Sanchez and Maria Sanchez.

• That's why his ghost is like a Day of the Dead spirit as opposed to your traditional rattling chains see through but still human looking ghost.

Mystery's mysterious antagonist Shiromori is responsible for the events at the cave.

Shiromori's name is Japanese for "White Forest" and she stylisticlaly resembles a corrupted version of a shrine priestess of some kind...but she has no feet, which is a trait more typical of Japanese ghosts. Incidentally, her highlight color is pink, a color already associated with the supernatural in this setting, and her name and outfit have white in them, which is traditionally associated with mourning in Japanese. Taken all together, she might be some kind of yūrei, which means she is quite possibly a restless ghost. Restless Japanese ghosts have a history of remaining connected to the physical realm due to a negative emotion—jealousy, grief, sorrow, hate, revenge.

However, yūrei are also typically locked into a specific haunting location and are traditionally unable to wander far from said location. If Mystery is a kitsune—which more signs are pointing to with the Japanese connection—and Shiromori is unable to reach him directly, she might have sent malicious spirits to affect those near him and try to force him to reveal himself (and hopefully be hunted down). This is why in the flashback, Mystery started walking after Vivi, but then turned to follow Arthur and Lewis—he sensed something in that direction that was not only wrong, but familiar.

In this case, Arthur was the unlucky, vulnerable individual who, due to his latent jealousy, didn't act as expected when the malicious entity possessed him, and instead of attacking Mystery, he instead turned on Lewis. This is also why Mystery didn't attack sooner, because biting off a chunk of Arthur without being totally sure of what's happening was not a good idea for a supposedly harmless dog, and he had expected to be the one in danger first, not Lewis. He had his Game Face on even as Arthur's arm was being possessed because he thought he'd need to fight a possessed Arthur, not stop him from pushing Lewis. The possessing spirit didn't give half a crap; it's just malicious, as you can tell by the expression on the possessed half of Arthur's face. Mystery was horsed to reveal himself too late to save Lewis, but he managed bite off Arthur's arm, which was still possessed, as shown on the official character profile page. The severed arm has hints of an eye in the palm... and a common trait of Japanese ghost possession of (nonliving) items is the spontaneous appearance of eyes, limbs, and mouths on the item. Technically Arthur's arm isn't alive anymore, so it's now able to be possessed by a dangerous Japanese spirit, that was sent by another dangerous Japanese spirit of a sort, all to bring harm to a third potentially dangerous Japanese (fox) spirit.

In short, Shiromori, for reasons unknown, may be a ghost has a grudge against Mystery, but also can't affect him directly. She tries to get to him through his friends, but her plan goes awry and the casualty of her plot is Lewis instead of Mystery (or Arthur, if Mystery had been required to use the implied extent of his kitsune abilities to fight the possessed Arthur).

• Seemingly Jossed as of "Freaking Out," where she is able to appear at the cave where Lewis died but does not seem to be capable of more accurately tracking Mystery in any way other than using her spirit flowers to try and build a chain of connections towards him. She does not seem to notice nor care about Arthur's severed arm AKA '???' scooting around in the beginning of the video. Additionally, said arm manages to have an Oh, Crap! reaction upon spotting her, suggesting that they are not allied in any form and that, like Mystery, the evil spirit possessing it has reason to fear her as well.
• Further Jossed as of "Hellbent." She doesn't have a grudge against Mystery, she's hunting him, and can definitely affect him directly by attacking him and drawing blood.

In the climax of the last video, Lewis will (seemingly) kill Arthur

Everyone's problems could be solved if they all stopped and talked it out, but this is a Mime and Music-Only Cartoon. So instead, Lewis will actually get his revenge on Arthur, maybe by pushing him off a cliff or something to mirror his own death. Then Lewis will try to reconcile with Vivi by revealing his identity, but she'll be a horrified by what he has done and refuse to accept that he really is the Lewis she knew. This will prompt Lewis' Heel Realization.

• Both confirmed and yet a little bit too far-sighted. Lewis appears to drop Arthur onto some spikes in a mirror of how Lewis himself died, but this happens in episode 3, "Hellbent." Lewis also instantly realizes how far he's gone the moment he lets go of Arthur and has to watch his former friend fall to his apparent death. He is clearly remorseful of his vengeful action.

One of the episodes will be a prequel.

The episode will be a prequel or flashback showing Mystery Skulls before the incident. The song will either be Magic or Number One detailing how Lewis and Vivi became a couple.

The green spirit is still trying to possess Arthur through his left arm, and is trying to make the gang forget about Lewis.

When Arthur's looking at the picture of everyone in Freaking Out, he presses a button with his robotic arm, slowly fading away Lewis (and inadvertently alerting Mystery). At the same time, and in the same color, as the edit, sleeping Vivi's eyes glow; while the Nightmare Fuel page claims that the glow means she's editing the page, it could very well be that the edit is trying to affect her memory. Note also that the arm is sparking as though malfunctioning when Mystery wakes up to glare at it - this could mean that Arthur isn't in control, and Mystery is trying to scare the evil spirit out of his friend.

Additionally, this could be the reason why her mirror in Ghost has blank eyes - she's being figuratively "blinded" to not only Lewis's fate, but also his entire existence by the spirit. As to why the spirit wants them to forget, it could be that Lewis was the one to get the gang into ghost-hunting, and that by removing him from their memories, they might forget all about the ghosts, leaving the spirit free to do mischief.

The character's accent colors give clues to their relationships with other characters.

More specifically, Vivi's pink glasses match Lewis' color scheme, hinting at their relationship and that she is "searching" or "watching out for him." In the same way, Mystery's glasses are yellow, relating to Arthur's color scheme. In "Ghost", Mystery is seen following after Arthur in the caves, and can be seen silhouetted in the background of Arthur's transformation scene, with only his yellow glasses visible.

On a similar note, Lewis' heart could also be representing his current person of interest. When whole, it is yellow, like Arthur, and he at least appears to mostly be concerned with vengeance, chasing after Arthur specifically and only directing his attention to Vivi when she gets between them. On the other hand, when his heart is broken, it is blue, like Vivi, and she seems to be the center of his attention. Notably, in "Freaking Out," Lewis notices and picks up Vivi's blue flower first, only noticing Arthur's when it moves slightly.

• Arthur doesn't wear any of his teammates' colors. He's isolated.
  • On close inspection, Arthur actually has a small blue pin and a black and white pin with red outlines on his vest in "Freaking Out" that were not there in "Ghost." Maybe his relationships with Vivi and Mystery have shifted in the time between the two videos.

Shiromori will try to hitchhike with Lewis

Since it's too early in the series for either of the two to win, Shiro will trace Mystery to the MS van but fail to capture him, instead being chased off in a bout of psychotic driving. Angry and unable to catch up to a speeding car, she'll try to track him down again only to find that there's not enough residual presence for her to draw from. Just then, Lewis will arrive late to the party, and upon realizing that they have a common destination, she'll try to get him to let her ride in his truck.

The series logo at the end of "Freaking Out" features the hood of said truck (including a small skull at the bottom) intertwined with vines. Plus, Mystery Ben suggests that Shiro's relationship with Mystery may be explored soon, which would fit if the next ep or two were Shiromori-centric.

• As of Hellbound's release, it turns out those Vines are on the hood of the truck because Lewis accidentally ran over Shiromori while chasing the Mystery Skulls van.

Lewis is related to the Necromancer from Yuracon's ''Magic'' animatic

I mean come on, just look at their designs and tell me you don't see a resemblance.

• To be fair, the character was based on a fusion of Lewis, Brook and Manolo, created by Yuramec/Yuracon.

Vivi has psychic powers

It's clear from the pink-eyed shadow in Vivi's profile pic that there is something abnormal about her. I believe that she has some kind of psychic ability. This would not only explain certain story elements in the series, but it would also make it so that everyone in the troupe has some sort of stereotypical paranormal role (a psychic, a cyborg, a monster in disguise, and a ghost if you count Lewis).

She doesn't know about them yet, but is able to use them subconsciously. Her brain seems to be using these powers as a mental defense mechanism. At first it just makes her (and probably Arthur and Mystery) forget about the events of the cave because watching her boyfriend die and her dog turn into a monster and rip someone's arm off was too traumatic. The glowing pink eyes were her powers manifesting themselves. Her powers retconned everyone's memories so that Lewis just "disappeared" and they had to go on some cool adventure to find him. However, in Freaking Out it looks like they've searched several areas without finding any sign of Lewis alive, and Vivi is beginning to lose hope. Thus, her subconscious is trying a new trick: actively scrubbing Lewis out of existence. This is why we see her eyes glowing as his picture is fading from the computer. If things go on too much longer, said powers might eventually make her and everyone around her forget that Lewis ever existed and remove all trace of him from photos, documents and other media.

• Not impossible, but Ghost shows that this is an effect of Lewis's powers. After he dies in the backstory montage, his locket / anchor discharges pink energy that flows into Vivi's eyes. She looks distraught and shocked, gazing downwards, where she probably saw his body hitting the stalagmites. The glow in her eyes and Lewis's image vanishing from the picture Freaking Out are the same pink as his powers. It's probably meant as a visual short-cut for the audience. He wiped her memories of his death - and, as it seems, also of himself.
  • If anything, Vivi has ice powers.

Arthur's lack of memories of what happened to Lewis isn't supernatural in nature.

He forgot about what happened to Lewis (and is now looking for him) because of good old fashioned trauma. The very traumatic event (being possessed, killing his friend, and the sheer blood loss from an injury like LOSING AN ARM) was enough to leave Arthur with no memories of what happened in the cave.

Shiromori is not evil.

We still don't exactly know why she's after Mystery, and it could be that she's not after him for the reasons we're thinking. A specific class of kitsune, "yako", is known to be malicious or even malevolent, and so it's entirely possible that Mystery was not quite a "good guy" in the past and Shiromori attempted to stop him. She probably wouldn't have any way of knowing that he's not manipulating the Mystery Skulls. After all, what with the entire backstory on Lewis, misunderstandings seem to be a major theme in the animations.

Shiromori is a Stalker with a Crush toward Mystery

The next video will be set to the song Hellbent. Let's look at some of the lyrics: "I've been hellbent, baby / Hellbent on loving you ... Hellbent on making you love me too." That sounds too stalker-ish to match the relationship between Vivi and Lewis, but what if these are actually Shiromori's feelings toward Mystery and he's just not interested?

Lewis, Shiromori, and ??? will team up

Right now there is roughly a 3 v 3 going on. Lewis seeking out Vivi (though he wants revenge on Arthur who is with her). Shiromori wants Mystery for whatever reason. Then you have ??? who took off, and may be seeking out to rejoin Arthur. This isn't to say they'll stay teamed up, namely Lewis and ??? if Lewis finds out what happens, but a team-up will occur. The third video may even be a bit ??? heavy to setup for this.

• Jossed for now. Shiromori and Lewis threw down in "Freaking Out" after she dared touch his broken heart and he knocked her block off, and Lewis followed it up by hitting her with a semi truck in "Hellbent." They're probably not friends. ??? is also nowhere to be seen after "Freaking Out," no doubt wanting nothing to do with three powerful supernatural entities fighting.

Lewis will come back to life and Arthur will die in turn.

Mystery is trying to communicate with Arthur

Consider the sequence with Mystery appearing to Arthur in his true form. Mystery watches the image of Lewis being magically edited out of Arthur's desktop picture with obvious anger, then the scene shifts to Arthur quaking in fear of Mystery in his true form as his cybernetic arm bugs out. Notably, Mystery appears in a visible Art Shift and appears to be glaring at the arm in question. This suggests that he may be a sort of projection, or an image in Arthur's mind. We then cut to kitsune!Mystery in the normal art style, taking up the whole frame, who initially glares down in concentration before doing an alarmed Aside Glance. Cut back to Arthur, suddenly jolting up as if from a Catapult Nightmare. Following this, Mystery is back to his dog form as Vivi rouses irritably, and acts like nothing happened. It's possible that Mystery may be trying to reach Arthur, to help him understand the truth of what has happened, but either Arthur keeps rejecting his attempts out of subconscious fear of him or he keeps having close calls with his cover being blown.

Shiromori is a Furutsubaki

Furutsubaki are the spirits of older camellia (tsubaki) trees, that tend to resemble human women when they appear to people. Camellias appear in pink and white, both colors associated with Shiromori, and the camellia is nicknamed the "rose of winter" (winter being associated with white—recall that Shiromori's name translates to "white forest"; a forest would look pretty white while covered with snow. In addition, Snow Means Death; note that she primarily interacts with Lewis in her debut appearance). Finally, the camellia is associated with longing and passion, fitting the themes of the series. If true, this might lend credence to the "Shiro is a Stalker with a Crush" theory above.

Lewis is only able to track Arthur and Vivi due to the flowers Shiromori left behind

Prior to Shiromori's arrival he made himself a haunted mansion and stayed sleeping in a coffin in its basement waiting for the crew to show up. He makes no move to chase them down when they first leave when he could follow them and he seems to track their location instantly after Shiromori leaves behind their flowers. He is not shown using the flowers to track anyone in the same fashion as Shiromori but it is one explanation for how he instantly knows where to go after acquiring his new wheels.

Lewis is partially a reference to the title of the Mystery Skulls song Soul on Fire.

Pretty self explanatory. He's a ghost and is heavily associated with fire. In Ghost: A burning heart (his to be exact) is part of the thumbnail, one of the first things his spirit does is light candles and a chandelier, he lights up bowls before revealing his haircut, he's shown holding a torch in the cave, and his hair turns into an explosion after Arthur grabs Vivi.

Lewis will be brought Back from the Dead in the end.

Especially since the band has recently released a single entitled "Back to Life"

Mystery created Shiromori with his blood and now she wants more.

During Hellbent, we see in one of the background images that flash behind Shiromori as she approaches him and Vivi that in the past, Mystery found a flower in a forest and then poured his blood on it. In the next image, Mystery is perched in some trees that have Shiromori's coloring while a blue haired warrior approaches. In the next flash background image, we see that he fought the warrior and got more cut up. His blood probably got on the trees, letting them absorb more and more of his power. After the end of the fight, the trees could have grown powerful enough to be self aware—and hungry for more of Mystery's magic. Shiromori is born of that hunger and sets out to get more of his blood/power. Look at how she reacts to seeing him bleed in Hellbent, after she breaks the windshield and cuts his cheek with her scissors. Her eyes go black and her smile gets more twisted.

Shiromori is actually a Jubokko.

The jubokko is a Japanese yokai that takes the form of a bloodthirsty tree, sort of a homicidal and vampiric kodama that has become desperately addicted to blood. This seems to fit with what we've seen of Shiromori and her implied background—that she sprung from a sapling that was watered with Mystery's blood, and now craves it even more. It also fits in with her botanical motif. Notably, a jubokko cannot technically be killed—snapping off a branch does not actually cause it any harm, it just bleeds like an animal. This is not too far removed from how Shiromori loses limbs and gets hit by vehicles, yet is none the worse for wear.

Lewis has no idea Arthur was possessed when he killed him.

In "Hellbent", the first of Lewis' flashbacks show him happily in a relationship with Vivi, with Arthur in the background looking really jealous. In the flashback of events in "Ghost", Arthur looks discontent, but not jealous. Then we see a flashback of Lewis' death, where the un-possessed and remorseful half Arthur's face is heavily obscured; you can barely see him frowning, much less shedding tears for his actions. This implies that, from Lewis' perspective, Arthur killed him in cold blood.

What's more, Arthur's mechanical arm (broken for most of Hellbent) sparks with pink magic and grabs onto Lewis just before he's dropped. The magic restoring power to Arthur's arm, and then Lewis' subsequent reaction implies that he expected Arthur to fight back, only realising the truth when Arthur makes no attempt to hold on.

Until Hellbent, Lewis didn't know for certain that the others couldn't recognise him.

The last thing Arthur does before Lewis drops him is call out Lewis' name. We can't hear the tone of his voice, but going from his expression when he says it, he's in shocked disbelief. That's what finally clues Lewis into the fact that Arthur didn't recognise him, but by that point it's too late.

Shiromori was a servant of Mystery's who rebelled when he weakened.

Mystery intentionally created Shiromori as a minion to fight the Blue Swordswoman. But the Blue Swordswoman stomped Mystery so hard he lost 2-3 of his tails. A 6-7 Tailed Fox is weaker than a 9 Tail by several degrees of magnitute. She moved against him to drain his blood once he no longer had power over her.

The true conflict isn't Lewis vs. Arthur or even Shinomori vs. Mystery, but Mystery vs. the green poltergeist.

It's possible that whatever possessed Arthur is the same force that Mystery fought against in his own time; his creation of Shinomori was a byproduct of his doing what a guardian kitsune would be expected to do: Banish the corruption from his territory. In doing so, he earned his ninth tail and tenko status. Vivi's ancestor attacked him thinking he was the source of the corruption (not a difficult thing to see, considering he's wearing a toothy, malign-looking smile and is perched over a samurai's corpse) and in the righteous vs. righteous battle that followed, he lost his coveted tenko status and a full third of his power. Banished from the heavens, he indentured himself as an inari kitsune to Vivi's family until he restored his lost honor.

TL;DR summary: The entire conflict was a case of Mistaken Identity, generating the demon that pursues him to the present day and allowing the Greater-Scope Villain to quietly hide - until the Mystery Skulls accidentally unearth it. And now Mystery has to finish what he started all those centuries ago, or be forever trapped in the mortal realm.

It sets up a Bittersweet Ending for the entire saga: If Mystery succeeds, he will finally banish the corruption and free the spirits trapped in its cycle of vengeance, and in doing so restore his tenko status - but it means he will depart the mortal realm, leaving Vivi, her family, and her friends without their beloved companion.

Vivi is part Kitsune, and Mystery is actually an ancestor of hers by blood.

The fight between Mystery and Vivi's ancestor when he was the height of his power ended in a draw after a lot of blood spilled on the grove of trees Mystery had been living in. The human warrior and the Kitsune both bloodied and bruised ended up finding some common ground which let them draw a temporary truce to recover since the fight had reached the limits of honor with no clear winner. Eventually that truce turned into something more when Vivi's ancestor had a kid with Mystery thanks to their mutual affection. However given Mystery is a Kitsune that could live potentially millennia before natural causes could even begin to become a problem their romance was short lived from his perspective before she eventually died.

The time with her fundamentally changed his point of view which lead him to adopt a more human like sense of morality rather then the Blue-and-Orange Morality that is standard for Kitsune. As a result he became their families guardian spirit after a fashion coming and going as time went on, staying for a few decades in disguise then disappearing when his kids, grandkids, etc eventually started to wonder why the family dog or cat was living so long. As time went on Mystery had to step in occasionally to save the lives of his decedents costing him a few of his tails over the centuries. He followed the family all the way to the United States when they emigrated from Japan and now spends his time following around his great-great-great however many generations granddaughter who has a fascination with the supernatural.

The only problem is that she actually managed to find something, something real, that forced him to drop his disguise ever so briefly and regain the attention of some of his many old enemies. Mystery is not a young Kitsune anymore and after all his centuries of service to his family he has been weakened by the wounds he's taken protecting them which is why he's scared. That and Vivi by some fluke has an unusually strong connection to her inhuman ancestry which is starting to manifest in the form of subconsciously erasing things from the world around her.

In "Freaking Out", Arthur was actually dreaming of a parallel universe.

This is the only explanation I could think of that would explain Arthur's weird dream. It didn't actually seem prophetic in any way, but the way the dream was told makes it just seem. Off to me.

At the end of “The Future”, Mystery got possessed by the green spirit that also possessed Arthur.

Mystery’s eyes were glowing green, as well as his body gaining a black and green color scheme, primarily used by the green spirit.

• Is this even a WMG? This is very obviously the case of what happened. Heck, we even see the green arm grab, what we can only assume is, Mystery's heart within the end of the video.
• This troper made this only after... a few minutes after “The Future” aired, so they were still processing everything that happened in the video. Very much *not* a WMG at this point.

Mystery forgot that he was a kitsune.

Like the rest of the Mystery Skulls, he too, lost part of his memories. This is why in the first episode his eyes had a sinister glow to them after seeing the video of him becoming a kitsune: he remembered his entire past and that he is indeed no ordinary dog.

Mystery considers both Vivi and Shiromori his children.

It would explain why he felt the need to protect both so badly, and why he looked so horrified at Shiromori's death at the end of The Future rather well. He could easily be so terrified of Shiromori earlier in Hellbent and Freaking Out not because of her threat to him, but because of her threat to everyone else. When Shiromori and Vivi fought, his own actions seem to be more that he wanted both to live, only truly attacking with intent to kill when it looked like there was no other option.

The green character/arm is secretely...

...Chloe, who canonically resents Vivi for not letting her join the Mystery Skulls. She wanted to break them up because she couldn't join, and was probably planning on turning Lewis into her "undead boyfriend", also as a form of jealousy. Plus, she's the only green character, and I'm fairly sure her colour matches the one in the cave.

Shiromori isn't dead just incapacitated.

Specifically because Vivi was using a baseball bat rather then a sword like her ancestor. As a result she knocked the crystal apple looking thing that serves as Shiromori's bind to the living world, not unlike Lewis' locket, into the distance. Mystery was still thinking of the last time one of Vivi's ancestors fought Shiromori and if that crystal doodad had been hit with a blade it would have shattered killing her. Instead she'll just need time to regrow or have it reattached to her old tree body.

• It appears that all it takes to revive a supernatural being is to grab their heart. After Shiromori grabbed Lewis' heart he revived a few seconds later, and the same thing happened to Mystery after the green spirit grabbed his heart.

[REDACTED] is working with this universe's Men In Black.

Hence why most of its profile is redacted, and what's visible is written in the clinical tone commonly associated with the SCP Foundation. As for who they are, what the nature of their alliance is, and what it means for our heroes, that's all up in the air for now.