Kill Bill/WMG

Rufus is Jules Winfield living under an assumed name.
Either he was still wandering when the Massacre occurred, or God had finally put him right where he wanted him.
 * This is now part of my personal canon. Thank you.
 * Playing piano at a church would be fitting job for the newly religious Jules.
 * He also mentions how he "walks the earth" playing piano all across the country. Jules Winfield said he would "walk the earth" at the end of Pulp Fiction.
 * In fact he said he'd walk the earth "You know, like Caine in Kung Fu" and ends up being killed in a massacre committed by...Caine, from Kung Fu.
 * Jules Winfield was based on a man named Saint Moses the Black, who was a criminal until he had a religious experience and became a monk, and then later a priest. He eventually died as an old man defending a monastery from a group of bandits, who killed him and seven others. Let's see...not counting, since they weren't killed, there were how many people? I believe... eight (Reverend and mother, four friends, groom, Jules Winfield). Eight.
 * Rufus was none other but FBI Agent Neville Flynn. Both films feature serpents... of a sort. Clearly his infiltration of a ceremony featuring a suspected assassin was one of his earlier missions. He didn't die, either. Blood packs.

Bill is actually a time-warped, evil version of Kwai Chang Caine from Kung Fu.
So, Pai Mei is the sort of evil martial arts master that taught Bill and massacred the Shaolin monks at some point. Bill is David Carradine, who plays Caine's trademark flute. Bill is obviously some weird, evil, alternate reality version of Caine that was raised by Pai Mei after he offed the monks.
 * Alternate reality, nothin'. Bill is the original Kwai Chang Caine. What can I say, that many years can change a man...and God knows what horrors Pai Mei put him through before deeming him worthy of the secret to eternal life.

Elle survived her encounter with the Bride.
The members of the Deadly Viper Assassination Squad have lived through worse than being blind in a trailer with a snake. The sequel will feature her as a blind swordswoman, which is hardly a setback in this business.
 * No. Elle will be the blind master who will adopt and train Nikki Green (Copperhead's daughter) to take revenge on the woman who murdered her mother in front of her. Nikki and B.B. (the Bride's daughter) will be best friends, attending the same school (they're both the same age). The Bride even said that she'll be waiting, should Nikki ever seek revenge.
 * And since Beatrix is no doubt now in hiding, Nikki will need to learn how to hunt a person down. Perhaps from a charming old German immigrant with an interesting scar.
 * Elle will be Zatoichi; Sofie Fatale will be the One Armed Swordswoman. That depends on whether the deleted scene showing Sofie's other limbs getting chopped off is canon, though.
 * There will be a hilarious scene where Elle and Sofie team up...and try to drive a car.
 * That would be an incredibly wasted opportunity
 * Jules Winfield will be there too, having decided that God led him to that church to witness the birth of a great evil. He will come out of retirement for one last job, and help Nikki kill The Bride.
 * No, Elle will team-up with another blind assassin: Special Agent Sands.

Kill Bill is the future of Rugrats.

 * Think about it for a minute. Angelica is The Bride, Suzie Carmichael is Copperhead, Lil is Elle Driver, Kimmi is Oren Ishii, Tommy is Budd, and Dil is Bill. Angelica's crazy as it is, Kimmi's Asian and not from the US, Suzie's black, Lil at the beginning of the series was the only other female peer, and Tommy and Dil are brothers.
 * The crazy 88 are the Mr. Friend dolls.

Kill Bill is an adaptation of the Fox Force Five television series, years after the fact.
Deadliest woman in the world with a blade, huh?
 * Yes, this does mean that Quentin Tarantino exists in the universe of Reservoir Dogs and Pulp Fiction.
 * This was already part of this troper's fanon, actually
 * Tarentino said in one of his interviews that he made Kill Bill so if the cast of Pulp Fiction and Reservoir Dogs would watch it they would like it.

The Yakuza thug with the white clothes who participates in the murder of O-Ren's parents is Bill.
He'd be about the right age, and he's evidently enough of a bastard.
 * Supposedly, this has been confirmed by Word of God.
 * It's almost indisputable - he has the same distinctive rings (and sword) that we see in the shot of Bill's hand when he's talking on the phone to Elle in the first movie.
 * My only problem with this is that, why the hell would O-Ren then want to work with him? He helped murder her parents; unless we're going to say she's completely dispassionate by that point, I don't see her allying with such a person.
 * She was hiding the entire time, so she probably never got a clear view of the killer, and never knew it was Bill.
 * Alternately, as a professional assassin, she only blames the person who calls the hit, not the killer.
 * This would explain a lot, and leads into...

Bill orchestrated most of O-ren's life as a brilliant power-play.
Bill was a higher-up in the organization of the Yakuza who ordered the deaths of O-ren's parents. He heard her "whim-per" in the room and stayed behind to collect her after setting the place ablaze, while the rest of the crew returned to the hangout. Children who witness their parent's deaths seem to grow up to be murderers in this universe (see Beatrix Kiddo's automatic assumption about what Nikita Green will do when she's older), so Bill decided to put this particular killer-to-be to work for him. He trained her to become an assassin, made sure she became one of the girls on the pedophile crimelord's list, and then smuggled her out, earning her loyalty. In the wake of his death, Bill seized control of the gang's resources and finances, then dissolved the group, leaving a huge power vacuum in the Japanese underworld and him with enough funding to start a lucrative assassination cartel: The Deadly Viper Assassination Squad. By playing one gang off another and killing key power figures in each faction, Bill ensures that the Japanese underworld will remain locked in bloody conflict for the next decade. He expands the his borders of operations around the globe, working other projects and jobs, but makes sure to keep Japan destabilized. Ten years later, when all of the Yakuza factions are weak, desperate and divided due to years of strife, he uses his influence and wealth to back the bloody rise of O-ren Ishii to head of the Yakuza and begin restoring the organization to glory. In a few years, one of the most powerful crime syndicate's in the world and the entire country its based in answer to a woman who holds him in utmost respect. With one fuckcrazy little girl, Bill slipped Japan into his pocket.
 * So Lucky Number Slevin without the Kansas City Shuffle then?...interesting....

The Bride started killing the Deadly Vipers with her best friend, and planned to finish with her worst enemy, before moving on to Bill.
Her comments when discussing finding O-Ren Ishii imply that there was more at work than expedience ("conveniently, the first name on my list was also the easiest to find..."), and in her confrontation with O-Ren there is an odd dynamic between the two, most notably in the shared line of "Silly rabbit, Trix are for-" "kids." Then, Vernita seems a little hostile, but remorseful; Budd is utterly dispassionate; and Elle openly hated The Bride even when they were on the same side. Plus, it suits her sense of drama.
 * Also, it adds an extra level of punishment for those later on the list: Extra time to know and fear that she is coming to kill them.
 * I agree that O-Ren and The Bride had been the closest out of all of the assassins working with Bill. I also think there was at least a lot of mutual respect. O-Ren understands revenge better than anyone in the vipers.
 * There's also the fact that the Bride knew O-Ren's whole life story, and narrated it for the audience.
 * Also, their battle was the longest if you count getting through the Crazy 88 and definitely the most honorable.
 * O-Ren also apologized after mocking the Bride. The Bride accepted the apology and asked if O-Ren was ready... something that she did not afford the others on her list. She also seemed somewhat remorseful when she fought her, implying that there was a part of her that still felt kniship with O-Ren.

Budd was expecting Elle to betray and attack him, but wasn't prepared for the poison of a California Mountain Snake.
It was repeatedly shown that Budd was a total Badass under his Corrupt Hick exterior, and an apt psychologist to boot. Why would he be caught off-guard by the hostility that Elle made clear even to the audience? He wasn't; Budd saw it coming a mile off and wanted to lure her into overextending before a swift shotgun blast to the torso, just as he did with The Bride. To prepare for this, he dosed himself heavily with the antidote to California Mountain Snake venom, knowing Elle's sick sense of humor. Unfortunately, he failed to account for the extent of her sympathy for her worst enemy, or attention to irony. Remember, kids, literary devices are Serious Business.
 * California Mountain Snakes aren't venomous.

O-Ren wasn't safe at the restaurant.
It's called the House of Blue Leaves. Obviously, the House had something to do with O-Ren's death. It might have even lead the Bride here somehow.
 * The House of Blue Leaves was built over the site of The Grudge house and has now an alluring aura for those seeking revenge.

O-Ren was intended to be the main character of the movies, but the Bride stole the role.
We learn a lot more about her than about the Bride. She has a tragic backstory, a strong personnality, a bunch of characters bound to her by a relationship that begged to be developed - even the mooks : they're mooks, but still she laughs with them and doesn't look down on them, and they're ready to die for her... In fact, the Bride was only supposed to fight O-Ren after having destroyed most of what she had built as the Queen of the Yakuzas, then be killed, leaving our half-Japanese swordswoman distraught at the end of Volume One. She then would have left her "job" in Volume Two and tried to find the other members of the Deadly Vipers looking for explanations on what they had done, the purpose of these murders, the story of the bride and so on. Eventually she would have discovered that Bill was, as explained above, the white-suited man who killed her father. Realizing she has been fooled into serving the man who had destroyed her life, carrying both her need for revenge and the Bride's memory, she would have become the Atoner and taken her revenge against Bill in a climactic fight, hence the title. But the fact is that the Bride is such a goddamn bitch, she managed to bend destiny itself, get up after having been killed by O-Ren when she cut her spine, and inverted what the scenario told by killing O-Ren, forcing Tarantino to re-write the story with her as the main character. Poor O-Ren.
 * That's actually a very clever theory. A No-Prize for you, my friend.
 * Interesting theory but why would O-Ren find anything unusual to look into? She knows why the Bride attacked her and her people, she was one of the one that tried to kill the Bride on Bill's orders. If anything after the Bride was killed by her she'd be happy, she'd ended her friend's pain after she put up a great fight and will be known as the one who killed the Black Mamba, boosting her reputation.

Bill wanted to die.
After dealing with the remorse for almost killing his true love and child he grew suicidal but couldn't kill himself (warrior's death and all). To make amends he took his daughter and tried to raise her as a caring and nuturing father. However when learning of Kiddo's awakening he made no attempts to stop her from getting to him. When the time came he put on the act as if he were fighting back and allowed Kiddo to kill him. If the fight were real it would have been much longer and Bill would be the victor, not without a few close calls himself. Instead he chose to die a good death and give the Bride her revenge and B.B her mother. Or......

B.B. is a tykebomb
Bill was too old and too weak while Kiddo still in her prime. In his younger days he would have very much been her equal, but years have been unkind. Bill devised a plan, to condition B.B., his daughter, to take his revenge. When B.B comes of age she'll turn on the Bride and possibly team up with Nikita to take revenge for their fallen parents.
 * That sequel would be amazing.

O-Ren was The Starscream of the Deadly Viper Assassination Squad
This goes in accordance with the theory that Bill participated in the deaths of O-Ren's parents. After tracking down Bill she joined the DiVAS in order to get close to him. Throughout the time she was a member of the group she tried numerous failed attempts on Bill's life. The only reason Bill kept her around was that he found her useful. It might also explain why Beatrix Kiddo went after O-Ren first. It was her way of saying that she's going to finish O-Ren's job for her.

The presence of Texas Ranger Earl McGraw confirms that...
The action films of Robert Rodriguez also take place in the Tarantino-universe. His cameo in Death Proof only cements this.
 * Also, Seth Gekko gets take out from Big Kahuna Burger, shortly after killing Earl.

Mia Wallace and Beatrix Kiddo are long-lost twin sisters.
We really don't know anything about Beatrix before she worked for Bill, and the only thing we know about Mia is that she wanted to be an actress. Bill seems to have a penchant for recruiting women with tragic pasts (evidence O-Ren). Mia and Beatrix's parents were horribly killed somehow and they were separated while still children. Jules Winfield (a.k.a. Rufus) probably noticed this, but never had time to approach Beatrix (a.k.a. Arlene) before the Squad attacked.

B.B. was awake during Bill and Beatrix's talk
I don't know how much she understood, but does know her mommy killed her daddy, and that's going to make for some interesting teen years...
 * Considering there were two gunshots and a lot of screaming during their talk, it makes a lot of sense that she would've woken up.

Bill told B.B. about her mommy waking up and coming for blood
He probably had a long talk to her after he confirmed the bride woke up. At volume two B.B. not only knew she will meet her mommy but the reunion will end with her losing one of her parents.
 * That would explain why she didn't wonder what happen to her dad.
 * Also why he made a point to explain that Daddy hurt Mommy before the final fight, so she would understand that Daddy had it coming

Gogo Yubari is (or was) a pair of Creepy Twins
They were twins in the original script: Axe Crazy Gogo at the bar and The Quiet One Gogo at the restaurant (Crazy!Gogo had the flu). Quiet!Gogo was killed and Crazy(er)!Gogo will avenge her in the sequel.
 * Tarantino originally wanted Chiaki Kuriyama (Gogo) and Kou Shibasaki (Yuki) as sisters (Chigusa and Mitsuko from Battle Royale respectively). Due to conflicting schedules, Kou Shibasaki was unavailable so Tarantino changed it to twins before scrapping thr idea altogether. (I would love to see Shibasaki in the sequel however)

The conflict between Bill and Budd is based on Bill's fondness for being "old school"
Bill likes to think of himself as a samurai or Ninja or something. He thinks in terms of honor, likes swordplay, has a flair for the dramatic, etc. However, Budd understand what they are: killers. Period, end of story. The dead don't give a shit if they were killed by an "honorable" warrior or not. What they care about is the fact that they're dead. So why should the killer care when the victim doesn't?

This self-realization is what allows him to be the only character who snags the Bride. He doesn't play by Bill's rules, which he knows she follows. I also think that this allowed him to be the most effective assassin in the group when they were still together. Because he didn't fuck around. It also likely makes him more like historical Ninja than anything Bill ever could achieve.

Gogo Yubari is a winner of a Battle Royale
The scene where she murders the businessman in the bar occurs just after she has been crowned winner and released. He was the first person she killed after the Program ended where she was forced to slaughter her friends. Her meteor hammer is the weapon she was randomly assigned, which she keeps as a souvenir. The schoolgirl uniform is her old school uniform, after being thoroughly washed. O-Ren was impressed by the teenage killer and bought her on board to her Yakuza Clan.

Pai Mei is a body jumping monster.
Gordon Liu's character defeated Pai Mei in the universe that Kill Bill shares with Kung Fu (ties in with the 'Bill is Kwai Chang Caine' theory above). Now Gordon Liu's character IS Pai Mei. QED, Pai Mei's immortality doesn't come from Dragon Ball Z style Training From Hell but rather from body snatching. The reason he's so dismissive of the bride and reputedly hates blondes, whites, and women is because they are completely unsuitable for him to groom as replacements. In order to keep the real reason of his immortality a secret, Pai Mei only possesses bodies with at least some similar characteristics to his original. This also makes Bill's "In the year Double-aught-three" introduction make a little more sense. Presumably when Elle poisoned him, rather than beating him in a martial challenge, the secret of his immortality was lost.

The Bride is still in a coma and all of the events of both films are just "dreams" or flashes of mental images that come to her while she lies in her hospital bed.
Let's review: The Bride was severely wounded in an attack and yet is able to leave the hospital, commandeer the "Party Wagon" and seek revenge against the people that injured her. Given the years of physical therapy that recovering from a coma would entail and the lack of obvious financial resources available to her, it's unlikely that The Bride would have been able track down highly trained, and one would assume extremely secretive, assassins. And since no matter how lopsided the odds or unlikely the circumstances, The Bride always overcomes and defeats her enemies, it's obvious that she is in a dream state and the movie series is a creation of her own imagination.
 * This also explains why people can bring swords onto commercial passenger aircraft and not arouse suspicion.
 * And why the only police we ever see in the movie are the ones cleaning up after the Massacre at Two Pines. If the whole story is all going on in the Bride's head, they don't belong in her revenge-fantasy.

Bill once said something deeply insulting regarding Hattori Hanzo's food preparing skills.
Hattori Hanzo has retired from sword-making, presumably for moral reasons. But when he learns that the Bride needs a sword to kill Bill, he oddly doesn't hesitate to forge one last sword. What has Bill done to him that makes him ignore his new principles?
 * A first hind comes from Budd. Upon hearing about all this, he remarks that it is typical for the Japanese to never forget a grudge they bear against someone. Bill and Hanzo indeed seem to have had a personal conflict back in the old days.
 * Then, when Bill and the Bride finally meet again, he asks her if Hattori Hanzo's sushi is still that bad. This indicates that Bil actually has tasted Hanzo's food. When has this been? When Bill still was Hanzo's pupil in katana fighting? Maybe, but a weapon smith who can't cook that good is hardly remarkable.
 * This leads us to the conclusion that Bill actually has once visited Hanzo's restaurant, probably shortly after Hanzo did retire and celebrated his grand opening. Back in these days, the two must still have been friends, because you'd hardly let your sworn enemy enter your house. Bill came as friend, tasted the food, was asked how he liked it, gave an honest answer - and departed as Hanzo's enemy.
 * I think Hanzo is supposed to be a good guy. I never watched the TV series but from what I understand, it's a long line of do-gooders who make really good swords. Bill took his training and swords and not only became an assassin but trained others to be assassins as well. Feeling betrayed, Hanzo retired and became a devout Buddhist.

Elle didn't really kill Pai Mei.
After hearing so much buildup and seeing Pai Mei's fighting prowess, it seems rather anticlimactic that a thousand-year-old master like Pai Mei would die from being poisoned at the hands of a lowly student, especially after being called an old fool. It seems more likely that Elle attempted to poison Pai Mei, but failed, and was thrown out by Pai Mei in a rare moment of mercy. Telling Beatrix that she had murdered her master seems exactly the sort of cruel thing that Elle would use as psychological warfare, and the flashback was just a narration of Elle embellishing the story. Not to mention, if Beatrix reacted violently to the news of Pai Mei being killed in such a cowardly fashion, imagine Bill's reaction. If Elle did kill Pai Mei, Bill likely would have killed her, or at the very least, suspended her from the Deadly Vipers.

The Bride, and possibly all the female members of the Deadly Viper Assassination Squad, were slayers or potential slayers.
Super strong women with insane martial arts skills who kick crazy amounts of ass? Bill is a former Watcher and picked them specifically because of this.

Winston Wolf will be in the sequel
The Wolf will clean up Vernita Green's house. Vernita's husband the Good Doctor Bell knows Bonnie, Jimmie Dimmick's wife. Bonnie knows her husband has connections and puts Bell in contact with the Wolf, who does help despite being retired after marrying Raquel from Monster Joe's Truck and Tow.

Pei Mei died before Budd could be trained.
Obviously, we know that  We don't know exactly when this happened but it's implied that it happened during her training. Now, the Bride had already gone through training and it seems that Vernita went through training with Pei Mei since she could go hand-to-hand with the Bride. Considering O-Ren was Bill's protege', we can assume that she also recieved training (we never see her martial arts skills). This would leave Elle as the last person to be trained and we know how that ended. Everyone seemed to have a low opinion of Budd's skill. Obviously, he let himself go, but when Bill asked if he was still practicing sword-fighting, martial arts never came up. Budd certainly didn't expect the Bride to punch her way through the coffin (seems that technique was the very first lesson.) He was next in line to be trained and it never happened due to Elle.

Pai Mei's training is the reason why the Bride survived the massacre.
Given that he's Really Seven Hundred Years Old, he's probably got some tricks for cheating death, and if he trusted the Bride enough to teach her the Five Point Palm Exploding Heart Technique, he would've trusted her enough to teach her how to survive grievous wounds, so that instead of dying when beaten and then shot in the head, she entered a Healing Coma. Bill didn't know about her learning the FPPEHT, which is why he chalked up her survival to mere chance. This also explains why the Bride was able to recover pretty quickly after waking up; she's able to mentally augment her healing. Note that this doesn't make her immortal; presumably, if she were caught totally off-guard (as Pai Mei was when Elle poisoned him), she'd still die.

Nikki Green will become a crime fighting super hero.
after her mother's death.

Bill had relationships with ALL the Di VAS (except Budd).
He's called "Snakecharmer". It's confirmed, straight up, that he had a relationship with the Bride, hell, he got her preggo. It's all but confirmed through his dialogue with Elle in the hospital, what with him telling her how much he loves her. We've never seen him interact with O-Ren or Vernita, why is it such a stretch to believe that he had similar relationships with them?There's actually a fairly prevelant fan theory that Vernita was pregnant with his baby during the wedding massacre because of how close BB and Nikki are in age...

During WWII, Bill (and possibly Budd) were Basterds.
After the original Basterds, Lt. Raine was ordered to put a new team together and do the same to the Japanese. Among the members were two young OSS agents who were familiar with Japanese martial arts and culture.