Aku‘s counterpart is somewhere in the universe.She has the same body shape(maybe rounder and softer)as Akuand some of his powers and she‘s made of the same material as Jack‘s sword. She and Aku are the only ones who can hurt each other physically.
The Dogs from Episode 2-3 will play into a crucial point of the movie (if it is ever made)
Aku is Nyarlathotep
Jack is not in the future nor has he ever traveled through time
The true ending of Samurai Jack...
Jack did not travel through time.The spell merely put him into suspended animation, possibly in an invisible/intangible state or pocket dimension. Either way, there's no going home for him.
Jack is unconsciously preventing his success.There have been several opportunities for Jack to get back, but he always ends up staying to help someone else. He's realized that if the timeline included his victory then Aku would no longer be around. Since Aku still exists in the future that mean Jack either failed to ever return or died in the past before he could defeat Aku. Since Jack doesn't want either to happen, he finds ways to justify staying. The scene that shows an older Jack making it through the portal (a vision Jack never got to see) happens after Jack decides to Screw Destiny or someone explains to Jack the concept of alternate timelines.
Jack is Aku.What, don't look at me like this! There's a possibility that Jack got corrupted by himself, thus, creating a Time Paradox and putting so many different timed and placed characters in an unique setting. Jack/Aku just had ripped the fabric of Time and Space apart, somehow or another. First hint is his true name never being revealed. Maybe The Scotsman went through some rip and is the true hero, as he'll save Jack from being corrupted through Power of Friendship.
Aku is the Unreliable Narrator of the series.In one episode, Aku reads fairy tales to children concerning some of Jack's adventures. Why not the whole series? Nothing else about it makes much sense.
Jack can't return home until he's defeated Aku in the future.If he returns to the past and defeats Aku there, the future will likely still exist as an alternate timeline, to be tormented by Aku for eternity. Jack will not be allowed to travel back until he destroys Aku in this time too, to give hope to the future as well as the past.
Jack's sword is a nexus of Spiral Power.Even gods needed to use something within the human spirit as raw materials. By extension, Aku is related to the Anti-Spirals. Then there's Robo-Samurai...
Aku is the spawn of ErebusIn the backstory, Aku emerges from a great darkness. The previous rulers were the Titans. Erebus in Greek mythology was the primordial darkness. It makes perfect sense. Of course, this means that it is likely false...
Jack is InsaneJack was never sent to the future. Rather, he was born in the future, and being one of the best warriors in the world, decided to create a persona with which to fight Aku. However, living in the dystopian future has driven Jack completely insane, and caused him to believe his own back story as a way of disassociating himself with a reality he hates. The rest is history.
Jack never ExistedThe entire series is a series of stories told by the parents of the children in Aku's future to give them hope. Jack never existed, and Aku rules unchallenged forever.
Jack will be battle his way Backwards in timeIt goes like this: Jack ended up finding a way to go into the past, but only a few hundred or thousand years. With a so long to go back, he will be forced to defeat Aku each time, slowly removing the stain of Aku as he goes until he can destroy him at the source, appearing in the time when Aku was either an unthinking darkness or trapped in the tree.
Aku is made of Chemical XAlso Jack is one of Professor Utonium's ancestors.
Continuing from the above, Mojo Jojo is Aku reincarnatedThe Chemical X that mutated Mojo came from a sample of an already slain Aku. Both have a black and green color scheme as well as a Japanese accent.
Jack's sword is a zanpakutoWhy the hell not?
The ending of one episode is out of chronological order...Which episode, you ask? The one where he learns to jump good. The episode ends with Jack jumping into the air, to attack Aku, who is holding what looks like a portal to the past. Ok, I know it's unlikely that by the end of the series, Aku won't know about Jack's ability to jump good...but damn it, I want to believe we have a canon resolution to the series.
Jack won't return to his own timeAssuming we get the movie this time, Jack will have two options He can return to his own time and fight Aku, or he can fight Aku in the present. At first, he'll be on his way to do the latter, but will realize that either A) the future world he's currently living in will still exist, and that Aku, having learned this, will actually change his mind about time travel, and ENCOURAGE Jack to do this, or B) The future world will cease to exist, as will all the people he helped, some of whom will never even have evolved due to the lack of Aku. Ultimately, he'll decide that, however tragic the enslavement of his people, and Aku's reign over Earth may have been, they aren't worth abandoning/sacrificing the future for, and he'll ditch his last chance to go to his past to have an epic final battle against Aku, and completely destroy him. The last clip we'll see is Jack's allies celebrating the defeat of Aku, and Jack smiling sadly, and walking away. Cue tears
Samurai Jack is a graphic novel written by Buttercup and drawn by Bubbles after they grow up.It would explain the previous reference to Townsville and the Talking dogs in the beginning, Jack's similarity to Professor Utonium, and why Aku seems like Chemical X personified. And if Bubbles was drawing, it would explain why every enemy Jack cut was a robot, and makes a lot of sense with the silent episodes as when the two had creative differences.
Aku is active during the Powerpuff Girls' time, and is the ruler of Monster IslandSo we know from that there's an actual place called Monster Island. Said island is, in fact, the PPG's version of Japan, still ruled by Aku, who has somehow been constrained to its borders since he conquered it in Jack's time. So, for the time being, he makes do creating monsters and sending them to do battle in the outside world, waiting for the moment for the stars to be right or something along those lines. Eventually, as we can see from the ruins of Townsville in Jack's first episode, it does.
Jack will stop Aku in the Future and PastBut he'll learn that there are hundreds, if not thousands of alternate dimensions. Driven by his desire to ensure that no one ever suffers Aku's terror, Jack will find a means to endlessly travel time and space, fighting Aku for all eternity. Yea, definately a bit of a downer ending, but it would show how bad ass Jack is if he were willing to sacrifice any chance of peace just to ensure that Aku never exists in any dimension.
Time travel double time!Jack will travel back in time to just a few minutes before he is sent forward. Then past jack and future jack will team up against Aku, where he will manage to send past jack to the future
Aku is the personification of all primal fearsIt's obvious.
Jack has in fact traveled through the portalsBut with Aku being a trickster not one has successfully sent him to the correct time, and most simply sent him to different places not far in time to let Aku prepare better. This is a pretty optimistic view of the series meaning jack has beaten Aku more times than what we have seen.
Aku will be killed by a Combined Energy AttackJack, in the final battle, will call for aid from everyone he's befriended in the entire series and lead them into a Final Battle with Aku (makes sense as they can help make sure Aku can't escape this time and deal with his minions). During the final battle, Jack is nearly defeated but all his allies (or possibly the entire planet, odds are Aku would broadcast the battle to the entire world to crush them if he won) transfer their rightious spirit into the sword (which was forged from rightiousness, thus can be powered by it). Jack then uses it to completely obliterate Aku in one attack.
Jack will return to the past...after training the Scotsman to kill AkuThe Scotsman is Jack's equal with a holy sword as well. So he teaches the Scotsman everything he knows to give him an even better chance and allowing him to destroy Aku once Jack returns to the past, giving the future a hero.
Aku won't be killed in battle but instead suffer a Villainous BSODJack realizes physically attacking Aku can't destroy him, but figures out a way to copy his moral personality into Aku. With a conscious, Aku suddenly is overcome with guilt for several eons of causing pain and suffering across the universe and begs Jack to finish him off. Seems like something jack would do.
Jack's father actually made things better instead of worseAlright, Jack's father is the one who gave Aku sentience and a physical form, yes. But while this may seem like a Nice Job Breaking It, Hero, it may have actually changed the situation for the better. Think about it, the formless evil that became Aku was slowly spreading out from where it landed, consuming all in its path, possibly consuming the entire planet if given enough time. By giving Aku a physical form, it changed Aku's intent from destruction of everything to conquest. Yes, the world under Aku's rule sucks, but at least it can support life and people, and animals, have somewhat adapted to it. Along with that, Aku's new form is fightable, dangerous and powerful, but something that can be outwitted and fought instead of simply destroying everything in its path. So despite apparently worsening the situation, Jack's father may have in fact improved it.
Aku's humanoid form is simply a type b Shapeshifter Default FormHe remains in it because its easier and he can maintain control. His true form has a drawl back that makes it not a good idea (like losing the sentience he obtained from Jack's father's arrow) and he's saving it for a One-Winged Angel transformation in the final battle (if we ever see it).
Ikra is not another personification of Aku, she is Aku's daughterShe is Jack's oppisite, not unlike Ying and Yang. She is both good and evil, she got the evil from her father and the good from her mother. In fact, Jack has to turn her against her father in order to finally defeat Aku. She may even be Jack's soulmate.
If the show continued, Jack would have been a Tragic HeroAlso, his weakness, his fatal flaw, would be a love of the fairer sex. In at least one episode, Jack was almost stolen away by a beautiful fairy woman. In the same episode, multiple enemies came and Jack took care of them easily, but the beautiful woman he almost fell for. I also recall another episode featuring a female bounty hunter who almost seduced him. If the show continued, Aku would have taken the form of a beautiful woman to trick Jack.
The Scotman's sword is Excalibur
the scotman's name wil be revealed in the movie
The Scotman's sword is  Excalibur.
Aku took over/made the InstrumentalityThe dogs in the first episode are Underpeople, and many places Jack visits are taken from different eras.
"Jack" is in purgatoryHe will never make it home, but will forever being haunted by it's closeness, being literaly in his grasp (the episode where he rescued a fairy, from a gargoyle, that could wish him home).
He can never be killed, he's forced to walk an eternity as an invincible person constantly wanted by the authorities (the episode where his own sword could not be used to kill him, in the hands of evil.
His god is vengeful for him letting AKU go. I beleive it will all end with his god picking him up on the final day of his purgatory, and hurling him for eons more into time where he will land before The Great and Powerful AKU, stripped of his defenses and skills, and will be used how his new lord sees fit.
The Scotsman's Wife is a descendant of Amy Pond.It explains so much.
Da Samurai is in fact Afro SamuraiThis means that Justice and Empty Seven either serve Aku, or else are being manipulated by him, and (no surprise) the video game is Canon Discontinuity.
Jack is in fact in Phyrexia.A world of machines that bleed oil ruled by an ancient evil?
The Scotsman is in the same situation Jack is.Either shortly before or shortly after Jack first attacked Aku, the Scotsman attacked and nearly defeated Aku with his magic sword. To avoid defeat, Aku simply threw the Scotsman into the same future Jack is. Since his machine gun leg is a somewhat modern weapon, Scotsman might have gotten his leg removed and replaced while he was in the future.
When the movie is finally completed, in the finale, Jack's real name will be revealed to be MakoBecause that would be just too perfect an homage to give the late actor who voiced Aku so spectacularly.
Episode LII is a troll episode.Not just because Jack fights trolls in that episode, but that this is a case of a Trolling Creator. The penultimate episode, fitting for the end of the series, is a flashback of Jack's childhood, particularly how he learned to fight some truly serious enemies. The final episode, on the other hand, is about finding a baby's parents. The first half of the episode is annoying due to the baby crying shifting into an out-of-nowhere telling of Momotaro, the second half is a series of unrelated events, and the ending is a non sequitur with Jack acting Out of Character, having surprisingly little concern over the baby or his mother. Over the course of the episode, Jack takes more damage from a random deer in the forest than from fighting the trolls or the bounty hunter. The very last shot of the series is the baby yelling, "Momotaro!" as a Battle Cry. This episode feels so unfitting as a final episode (and Cartoon Network made it no secret that this is the end of the show), it had to have been intentional. Avatar The Last Airbender. Anyone else is preposterous, really.
Aku is the ancestor of the Uno family from Codename: Kids Next DoorTo see that his bloodline continued, Aku had a child with a mortal woman. This bloodline eventually produced Grandfather, who had his sons, Benedict (who also inherited dark powers) and Monty (who's soul was too good to gain the same dark powers). This means that when he gets older (knowing KND, probably 13) Nigel will have the same abilities.
The Scotsman is the Chosen one to go through the portalYeah I know, but wait one second. Let's list what we know. A: Chosen one not Jack B: Aku, who was given life by Jack's Father has some reason to want the Scotsman dead. C: The Scotsman is from the future, Jack is from the past and now in the future. So Jack stays as a hero in the future while the Scotsman leaves for the past to save it.
All English speech in the series is the result of Translation Convention.While it's never made clear just how far into the future Jack has traveled, it appears that the amount time is at least over a thousand years. Jack never seems to have problems with the expected language barrier. There are a few episodes, such as "Jack in Egypt", that indicate Jack knows multiple languages, one would expect that any language he knew would be incomprehensible to anyone in the future he was sent to. The answer to this is that since Aku is originally from Japan, he spread the use of Japanese throughout the Earth as he took over the world, similar to how countries like Britain, France, and Spain historically spread their languages as their empires grew. The homogeny of language also means that lingual drift would occur very slowly or almost not at all. Japanese as Jack knows it and the Japanese of the future has very few differences in terms of intelligibility. At worst his speech might sound a bit archaic to some in the same way some one speaking English from the 16th-17th century would sound to a modern speaker.