In all three of his appearances, Abe Lincoln takes pot-shots at the Republican party. This is odd considering that he was a republican and his opponents (and the people he fought in the Civil War) were primarily Democrats.
Maybe he's upset with how the Republican party has changed since his time? The Republican Party of the 1860s and the Republican Party of the 2000s are very different from each other. Not to mention that in his first two appearances he only criticizes McCain and Romney individually, as well as Obama, who is a Democrat. He doesn't make any statements toward either party as a whole in those and in in his third appearance, while he criticizes the Republicans for nominating Trump, whom he shows a dislike for, he doesn't speak of any of the party's policies and let's just leave it at that.
The rap was a time loop until he ended. Subsequently it is kinda hard to sort out past from future, so he could have regenerated into a past incarnation instead of a future one easily enough. Also, regeneration is a random process. No rule he can't have the same face twice, or even one we'd never seen before..
It is implied in Day of the Doctor that eventually, the Doctor will regenerate back into Tom Baker and take on the role of the Curator, as he was revisiting some of his previous incarnations, but "just a few old favorites". With this in mind, it's perfectly possible that he revisited David Tennant's incarnation, and the regeneration seen in ERB is his regeneration into the Curator.
Doc Brown managed to get his hands on a Dalek and made modifications that allowed him to control it via remote, as he does with the Delorean in the first movie. He could have easily modified it with a flux capacitor, giving it a temporal weapon.
He's had more than a few official photo ops shirtless, which many people find hilariously vain for a head of state. It's become rather Memetic on the Internet.
Why does Lenin claim that Stalin was "supposed to be his right-hand-man" when he specifically did not want Stalin to succeed him and saw Trotsky as his second?
It may have been intended as a Take That! towards Stalin's efforts to rewrite history by claiming he was Lenin's right-hand man. His next line immediately points out that for Lenin's supposed right-hand man Stalin did absolutely nothing to respect his memory. Also, Stalin was supposed to be Lenin's right-hand man, and served as such for most of Lenin's reign. That doesn't mean he was supposed to be his successor, and it's the shriveling of Stalin's loyalty and the growth of his ambition that led him to start turning General Secretary, the right hand of the Communist Party, into its leader so he could take control.
How does Wilbur Wright pull his dress shirt off when it's both buttoned and under a pair of suspenders?
Why do the Wright brothers say they're "representing North Carolina" when they are from Ohio? The first flight was made in North Carolina, and Rhett and Link are from North Carolina, but that's still no excuse.
"North Carolina" fits the beat better than "Ohio."
Why does Joan of Arc claim to be "The Maid of Orleans" when America hadn't even been discovered yet?
The Rasputin vs. Stalin rap has all of the rappers being very expressive in their speech and movements. Then you get to Putin, who stands perfectly still save for the occasional ineffective flop of his arm, talking like he just came out of a Rocky movie.
Putin is mainly expressionless most of the time. Think of Dull Surprise.
Kubrick gave AI: Artificial Intelligence over to Spielberg, and Kubrick is famous for being very perfectionist, yeah, but why claim it was a "waste of potential" when if someone should know Spielberg was Mis-blamed for a lot if it, it should be Kubrick whose ideas Spielberg was struggling to integrate into the movie?
What he's saying is he didn't like the way Spielberg handled the film. The Chris Rock cameo definitely doesn't seem like something Kubrick would put in.
"I'm still wanted, you're forgotten! People these days are watching Dexter!" Did Jack the Ripper just forget about the more recent success of Hannibal?
Yes. The point of a rap battle isn't to tell the truth, it's to insult the opponent.
Also, Hannibal's ratings were never all that good, hence why it was cancelled after three seasons. Dexter lasted eight.
Why are the three Western philosophers (Nietzsche, Socrates, Voltaire) even fighting on the same side, if the first dislikes the second and the second dislikes the third?
Rivals Team Up, or at minimum Enemy Mine. And it's not like the Eastern ones (Sun Tzu, Confucius, Lao Tzu) didn't have their differences amongst them, it's just in their case it was self-inflicted (by way of Sun Tzu's aggravation).
There are a few lines flung insultingly that don't sound very insulting. Two that come to mind are...
The Easter Bunny's statement that the Great Wall couldn't keep Khan out of China. Even disregarding that it wasn't a single wall yet, wouldn't "not being stopped by fortification" be a positive feature?
In the lines of "your persistence makes me sick".
"China" is a slang term for female genetalia.
Sherlock's buddy Watson taunts Batman on his lack of superpowers. Batman. The guy who thrashes a number of superpowered villains on a regular basis with nothing but his utility belt. Wouldn't that be a point of pride rather than shame?
Because Batman (and his fans) is argueably at his worst when he's having a pissing contest with the other superheroes of his universe who do have superpowers. And because anger makes you stupid, it seems Watson's trying to bring out Batman's infamous ego that's on display in these comparisons and throw him off his game.
Rap battle disses aren't really meant to take into account the nuance of a situation. As far as the battle is concerned, the fact that he's less powerful than most of his fellow heroes is a diss, the fact that he can still beat them is irrelevant.
It's not his lack of superpowers they are dissing, it's his reliance on his gadgets.
Master Chief claims Leonidas is "the soldier they need [him] to be". And... what?
Soldier They Need You To Be is the lowest rank of a soldier in Halo.
It also likely means Leonidas is the minimum (what they need), while when paired up with the first half of the line, Chief is so great that his sins were worthy of a monument. Plus, you know, names of achievements from Halo games.
How come Sun Tzu was in the lineup in the first place? He's a military genius, not a philosopher.
He was both.
Why does everyone treat Charles Darwin's last line ("It was hard losing my daughters and their brother / As hard as the wood that Oak gave your mother") against Ash Ketchum as some super huge burn? When you think about it for more than two seconds, it was a pretty run-of-the-mill "X Your Mom" joke, and X in this case is someone who's a pretty decent guy and practically a father figure to Ash - not to mention it's obviously (likely) untrue. Usually insults of that caliber require X to be someone the opponent hates (in this context, it could've been a member of Team Rocket, or one of Ash's rivals), if not the person using the dis themselves. It was made only slightly clever by mixing in an "oak wood" pun - and, of course, it's an extremely overused joke/theory that's been around since Pokémon first ever came out. All in all, it was actually very bland. So why does everyone treat it like it was the ultimate ending line that would leave Ash burned beyond recognition?
It Makes Sense in Context. Ash took a cheap shot by bringing up the deaths of three of Charles' children. Charles, while clearly furious, retained his pose, admitted that yes, it was hard for him, and then used this as setup to return the favor by making a joke at the expense of Ash's mom while implying that the man he admires so much is secretly banging her without his knowledge. Even if not true, the joke is very common in the Pokémon fandom, so, it's not as if Charles was making it up, it was more of a "you know what everybody's saying" thing.
Catherine the Great's first line is "Macedonians, Prussians and Romans. Those aren't worthy opponents. It takes a Russian to take down a Russian." But she wasn't Russian herself; she was a German princess who married into the Russian imperial family. Even if she's ignoring her origins and saw herself as Russian, why didn't Ivan call her out on that?
"But your loyalty withered up like your right hand, man!" But everything I can find on the net says it was Stalin's left arm that was shorter and smaller due to a childhood accident, although there's no clear consensus on what it was.
This line was made erroneous on purpose; after it is delivered, Stalin looks confused at his right hand.
The point of Al Capone vs Blackbeard is to see which one is a more terrifying criminal. So why would "my kids dress up like you for Halloween" be used as an insult rather than a compliment?
He's basically saying that Blackbeard is just kids' stuff compared to Capone. Dangerous criminal or not, you can't deny that Blackbeard is a Historical Domain Character and that pirates in general are a popular element of children's stories - and therefore, Capone says, Blackbeard is impossible to take seriously because of how pirates like him are commonly portrayed in media.
Caitlin Jenner tells the Hulk that if he thinks he is well-dressed, "your lying, which means you need a new wardrobe!" C. S. Lewis was good friends with J. R. R. Tolkien in real life, so why couldn't that line be used in Tolkien's battle from four episodes earlier instead of in a battle where neither rapper has the slightest thing to do with Narnia?
They maybe hadn't thought of it when they wrote Tolkien vs Martin. Given that many outside references are made in Caitlyn Jenner's verse, it may have been No Shame's idea to make the pun.
Why did Peter play Jamie Hyneman and Lloyd play Adam Savage? It's pretty obvious that the real Jamie looks more like Lloyd and the real Adam looks more like Peter. You might think it's to preserve the Red Oni, Blue Oni dynamic, which is also why Peter played Frank Sinatra and Lloyd played Freddie Mercury...oh wait.
Why were the Western philosophers all representatives of different nations and eras of thought spread over thousands of years while Eastern philosophy is represented by three Chinese guys who were alive at the same time?
Most Americans are more familiar with western philosophy. Lao Tzu, Sun Tzu, and Confucius are the only three eastern philosophers that most Americans would be familiar with.
Where did Joan Rivers get Robin Williams's lamp?
Seeing that the two were great friends in real life, Rivers probably took the lamp after his death (Williams died before her) as a Tragic Keepsake, as well as an Improvised Weapon.