Clara getting Missy (the Master) — who has just vaporized two people and is threatening to kill a third one — to listen to reason and to actually let the frozen planes go, which is a pretty impressive feat in itself. Not to mention that this kind and gentle schoolteacher is shown preparing to order UNIT snipers to kill Missy at her command.
The Doctor's grand entrance to his duel with Bors; riding a tank, playing the show's theme on a battle axe electric guitar.
Davros, whilst dying and confined to a life support machine with none of his normal energy left, still manages to steal the spotlight as the episode's Big Bad. He verbally challenges the Doctor's morals, using the Doctor's past actions and speeches (with more than a few footage callbacks) against him, and then reduces the Doctor to a begging mess when Missy and Clara are exterminated.
The reveal that Skaro has been rebuilt is enough to scare Missy shitless. Missy, the woman who vaporizes people about as casually as flicking their nose. Yeah, it's that bad, and really emphasizes how awesome the Daleks are, in both senses of the word. Extra points must go to the reprise of "The Dark and Endless Dalek Night" from all the way back in Series 4!
All of the experiences with the companions of the Doctor have resulted in UNIT deciding to cut to the chase and directly call Clara in when there's a crisis. And Clara has worked with him long enough to know that thousands of frozen aircraft in the sky won't be interesting enough for him (or at least this version of him) until they know more.
The Doctor riding into the Daleks' control room, in Davros' chair.
The Doctor: Admit it! You've all had this exact nightmare.
And then pulling out a cup of tea and a saucer. How? He's the Doctor, just accept it.
The Doctor seeing through Davros' Wounded Gazelle Gambit and using his regeneration energy to turn the decaying, decrepit Daleks on the others.
"One word. Er, no, two words, actually. First word, moron. Second word, sewers."
The Doctor destroying the Hand Mines to save a young Davros, instilling in his future self a vestigial sense of mercy that was transferred, however mildly, to the Daleks.
Also, the Doctor's hatred for guns is well known. He probably hasn't fired a gun in centuries, but he doesn't waste a single shot.
Davros' plan is pretty awesome in itself. He gives a performance so good, it makes sense that so many of the Kaled scientists in the years leading up to "Genesis of the Daleks" never realised what he was planning.
Kudos to Davros; he actually has survived among several billion trigger-happy mini-tanks for centuries - the only thing that actually got close to killing him (and, at one point before a Dalek interfered, was successful in killing him) was one of the Abominations of the Time War! Deranged megalomaniac he is... stupid he is not.
The Doctor giving a fourth wall-breaking lesson about the Bootstrap Paradox, using traveling back in time and becoming Beethoven as an example. He finishes the lecture with an electric guitar riff of the 5th symphony, before a kick-ass electric guitar version of the show's theme (reportedly played by Capaldi himself!) plays over the intro.
The Doctor's badass speech to the Fisher King. Followed up by tricking him to his own demise.
Fisher King: You will be a strong beacon. How many ghosts can I make of you? The Doctor: You know, you've got a lot in common with the Tivolians. You'll both do anything to survive. They'll surrender to anyone. You will hijack other people's souls and turn them into electromagnetic projections. That will to endure... that refusal... to ever cease. It's extraordinary. And it makes a fella think. Because you know what? If all I have to do to survive is tweak the future a bit, what's stopping me? Oh, yeah, yeah, yeah, yeah, yeah. The ripple effect. Maybe it will mean that the universe will be ruled by cats or something, in the future. But the way I see it, even a ghastly future is better than no future at all. You robbed those people of their deaths, made them nothing more than a message in a bottle. You violated something more important than Time. You bent the rules of life and death. So I am putting things straight. Here, now, this is where your story ends.
The Mire are a merciless race of intergalactic raiders with high technology weapons and they get tricked into retreating by a group of fishermen, farmers, two storytellers and a schoolteacher. Then they are blackmailed to staying away with a record of such a humiliating loss.
The Doctor realises why he frowned the face he got in this Regeneration - Donna can't be there to remind him to "save someone" so this new face will do it for her.. He's a Doctor, so he's going to do what a Doctor does - save someone from dying, the consequences be damned.
The fact that the Zygon rebels pulled off a pretty effective plan. They've been working on their "invasion" for under a year at most, and no one, be it UNIT or the Doctor, noticed. Ineffective villains, they are not.
Not quite no-one. Osgood was already investigating when everything kicked off, and it was only the rebels' speed that prevented her from getting out in front. Splendid girl. Both of her.
She messes around with Bonnie's bazooka aim just enough to make her miss with the first shot and then delay the second one long enough for the Doctor and Osgood to escape.
Clara also took advantage of her Psychic Link with Bonnie to tell the Doctor she was safe. She did so by taking control of Bonnie's hand and using it to send a text to the Doctor. She made it without having Bonnie notice it and without looking at her phone, and despite that she got the text right and sent it to the right number.
The Doctor'sepic rant about the futility of Bonnie's plan and the poisonous nature of cycles of revenge and war is one of the most badass speeches on the need for forgiveness to break the cycle ever given in fiction or in real life.
The simple fact that the episode takes on what had by this point long become a stodgy cliché of the Found Footage horror story, and actually makes it work by making an asset of the basic contrivance of all such stories, that there's always a convenient camera around to record everything, important.
Clara's choice to Face Death with Dignity. Unlike everyone else, she doesn't run, and has the moral withal to forbid the Doctor from taking vengeance.
Usually, the Villain Of The Week is anything but frightened of the Doctor until he defeats them; this time, when the Doctor gets angry, Ashildr, quite rightfully, basically shits herself in terror!
The Doctor's first trip into his imaginary TARDIS when he makes a seemingly suicidal jump, revealing that every single stray action he took in the preceding scene was designed to test if he could survive it, and as soon as he realized he could, he went for it.
He wasn't even doing those things to determine if he could survive a jump: it's the sort of thing he does all the time. Just in case what he learns comes in handy later. The Doctor's perception is one non-stop Sherlock Scan.
The Doctor is trapped in a castle made to screw with him. He has no way of beating the monster that is chasing him, and there's a handy-dandy re-spawn generator around, so he can die over and over again — trouble is, he re-spawns without his memory, so he has to start over each time. The monster will let him go if he tells it about the Hybrid, which the Doctor is unwilling to do. Between him and freedom is a substance that is four hundred times tougher than diamond. He works out at the last minute what is happening each time around, and concludes that rather than giving in he should punch the wall repeatedly until it gives way. Four and a half billion years later, the Doctor breaks free of the castle, ready to rain fire down on whatever started this. To reiterate, he punched his way back to Gallifrey.
"I'm going to get out of here, and find whoever put me here in the first place, and whatever they're trying to do, I'm going to stop it! But it might take me a little while, so do you want me to tell you a story? The Brothers Grimm, lovely fellas. They're on my darts team. According to them, there's this emperor and he asks this shepherd's boy, "How many seconds in eternity?". And the shepherd's boy says, there's this mountain of pure diamond. It takes an hour to climb it, and an hour to go around it! Every hundred years, a little bird comes and sharpens its beak on the diamond mountain. And when the entire mountain is chiselled away, the first second of eternity will have passed! You must think that's a hell of a long time; personally, I think that's a hell of a bird!"
Each time the Doctor figures out what's going on, the monster catches him — but although it doesn't kill him on the spot, it does leave him in an awful amount of pain. That means he's got to get back to the re-spawn generator to give himself another go - which in the condition the monster leaves him in, horribly burned and slowly dying, takes him about a day and a half. Countless iterations of the Doctor go through this, and every last one of them manages to make it in time, none of them willing to give up. He definitely proves his words at the beginning: "I will never, ever stop." Basically, the Doctor could confess, but the Doctor is one of the most stubborn things in the known universe, so he keeps going until he wins.
For the first ten minutes of the episode proper, the Doctor doesn't say a single word. He silently stays with a group of Gallifreyans in the barn where he ended the war, and when the military shows up to arrest him, he simply draws a line in the sand. As he walks forward, the gunship draws back to keep him in front of its guns. None of the Time Lords who show up dare to cross it, so Rassilon himself shows up, and the Doctor finally speaks: "Get off my planet."
Rassilon: Who the hell does he think he is? General: The man who won the Time War, sir.
Rassilon eventually returns with a group of soldiers and orders them to shoot the Doctor. They all intentionally miss him, refusing to kill somebody who served by their side during the Time War. One soldier drops his gun and walks over. Then another soldier follows, and another, until every other soldier has followed. Then, a trio of gunships shows up, and the Doctor reveals he called in reinforcements earlier. The Doctor successfully overthrows and banishes Rassilon through sheer reputation, without even having to lift a finger.
The General: Lord President, with respect, get off his planet.
Getting to see the original TARDIS interior is a long-time fan's dream. It's especially awesome since it was supposed to appear in an earlier episode which ended up not having the budget for it.
"You're monsters. Here you are, hiding away at the end of time. Do you even know why? Because you are hated. You are hated. By everybody. But by nobody more than me."
Understated but touching example: when the first gunship comes to the Dryland to demand the Doctor surrender himself to military custody, none of the Drylanders budge when ordered to get out of the way. They have no weapons or authority whatsoever, and know that thee Time Lords in the Capitol don't care about their welfare, yet they refuse to leave the line of fire if it means abandoning the Doctor.
River: I'm an archeologist from the future. I dug you up.
She made sure that she and the Doctor were standing in the exact spot where they would be protected from the meteor shower. Even better? She made sure it was a ship filled with some of the universe's worst murderers, cutthroats, and despots, so that the universe would lose some horrible people and, more importantly, there would be no obligation from either her or the Doctor to save anyone but themselves meaning that they can get down to getting stuff done.
How the Doctor finally takes down King Hydroflax's robot body. As it is lacking a "proper" head and believes the Doctor's head is a viable option, the Doctor goads it into accepting a bank transfer orb, promising it lots of money. When he places it into the empty head slot of Hydroflax, all the firewalls of all of the banks in the galaxy attack and overwhelm its systems, which allows the Doctor to escape.
For someone who hates endings, the Doctor accepting that it really is time to say goodbye to River. He could've flown off so easily, but once they crash-land, he never really even considers it, just decides to make it as nice of a night as possible.
epic rant about the futility of Bonnie's plan and the poisonous nature of cycles of revenge and war is one of the most badass speeches on the need for forgiveness to break the cycle ever given in fiction or in real life."I don't understand? Are you kidding me? Of course I understand. I mean, do you call this a war, this funny little thing? This is not a war, I FOUGHT IN A BIGGER WAR THAN YOU WILL EVER KNOW, I DID WORSE THINGS THAN YOU CAN EVER IMAGINE, AND WHEN I CLOSE MY EYES, I HEAR MORE SCREAMS THAN ANYONE COULD BE ABLE TO COUNT! And do you know what you do with that pain? Shall I tell you where you put it? You hold it tight, till it burns your hand. And you say this: No-one else will ever have to live like this, no-one else will have to feel this pain. Not on my watch."