Variant of a suggestion from Reddit: the original is to transfigure the Earth into gold for a nanosecond, along with a trail that reaches out to the Pioneer probes. The goal being to hit all horcruxes at once, and at the same time transfigure the death eaters and LV to kill them horcrux-less. This is supposed to 'work' because it's for a short amount of time.

Bearing in mind that the magic cost is dependant upon target size, I'd like to suggest another option: transfigure the cubic kilometre below them into a small diamond, or better yet, transfigure it into a slew of tiny bullets travelling at 0.1c and aimed everywhere except a cylinder centred on Harry. The target size (the bullets) is small, so this is feasible in a short time frame whilst causing mass disorientation as everyone suddenly is hit by 1g downwards acceleration and 0.1c bullets.

If I've misinterpreted the phrase target size, be aware that the opposite plan is also OP: simply transfigure the layer of dirt you're standing on (if that's what target means) into a 2km tall tower, then apparate.

If Voldemort was being careful he'd have taken away Harry's wand.

Harry only need to move his wand enough to touch his leg. Assuming his hand is already pointing down, this shouldn't be hard. He can then transfigure either the skin on his legs, or possibly the earth in front of him.

Can we each propose a non-transfiguration solution? Even if it's just a rough idea. I feel like we're getting stuck on transfiguration, and a bunch of those require very precise handling of things 10 feet away (such as death eaters) or significantly big things (Harry's body parts). Hermione struggled to get the stunning hex right on the first try, and I feel Eliezer will categorize "transfigure this very precise, remote thing" as a "new magical power".

I may be misinterpreting, but I thought the whole resonance business got cleared up when Voldemort lured Harry into shooting at him.

Pessimistic Assumptions Thread

"Excuse me, I should not have asked that of you, Mr. Potter, I forgot that you are blessed with an unusually pessimistic imagination -"

– Ch. 15

Sometimes people called Moody 'paranoid'.

Moody always told them to survive a hundred years of hunting Dark Wizards and then get back to him about that.

Mad-Eye Moody had once worked out how long it had taken him, in retrospect, to achieve what he now considered a decent level of caution - weighed up how much experience it had taken him to get good instead of lucky - and had begun to suspect that most people died before they got there. Moody had once expressed this thought to Lyall, who had done some ciphering and figuring, and told him that a typical Dark Wizard hunter would die, on average, eight and a half times along the way to becoming 'paranoid'. This explained a great deal, assuming Lyall wasn't lying.

Yesterday, Albus Dumbledore had told Mad-Eye Moody that the Dark Lord had used unspeakable dark arts to survive the death of his body, and was now awake and abroad, seeking to regain his power and begin the Wizarding War anew.

Someone else might have reacted with incredulity.

– Ch. 63

Under standard literary convention... the enemy wasn't supposed to look over what you'd done, sabotage the magic items you'd handed out, and then send out a troll rendered undetectable by some means the heroes couldn't figure out even after the fact, so that you might as well have not defended yourself at all. In a book, the point-of-view usually stayed on the main characters. Having the enemy just bypass all the protagonists' work, as a result of planning and actions taken out of literary sight, would be a diabolus ex machina, and dramatically unsatisfying.

But in real life the enemy would think that they were the main character, and they would also be clever, and think things through in advance, even if you didn't see them do it. That was why everything about this felt so disjointed, with parts unexplained and seemingly inexplicable.

– Ch. 94

"You may think that a grade of Dreadful... is not fair. That Miss Granger was faced with a test... for which her lessons... had not prepared her. That she was not told... that the exam was coming on that day."

The Defense Professor drew in a shaking breath.

"Such is realism," said Professor Quirrell.

– Ch. 103

Recalling finewbs's coordinated saturation bombing strategy, if the goal is to maximize the total best-guess probability of the set of scenarios covered by at least one solution, this means crafting and posting diverse solutions which handle as wide a diversity of conjunctions of pessimistic assumptions as possible. This would be helped by having a list of pessimistic assumptions.

(It also may be helped by having a reasonable source of probabilities of scenarios, such as HPMOR predictions on PredictionBook. Also: in an adversarial context, the truth of pessimistic assumptions is correlated.)

Pessimistic Assumptions Thread

"Excuse me, I should not have asked that of you, Mr. Potter, I forgot that you are blessed with an unusually pessimistic imagination -"

– Ch. 15

Sometimes people called Moody 'paranoid'.

Moody always told them to survive a hundred years of hunting Dark Wizards and then get back to him about that.

Mad-Eye Moody had once worked out how long it had taken him, in retrospect, to achieve what he now considered a decent level of caution - weighed up how much experience it had taken him to get good instead of lucky - and had begun to suspect that most people died before they got there. Moody had once expressed this thought to Lyall, who had done some ciphering and figuring, and told him that a typical Dark Wizard hunter would die, on average, eight and a half times along the way to becoming 'paranoid'. This explained a great deal, assuming Lyall wasn't lying.

Yesterday, Albus Dumbledore had told Mad-Eye Moody that the Dark Lord had used unspeakable dark arts to survive the death of his body, and was now awake and abroad, seeking to regain his power and begin the Wizarding War anew.

Someone else might have reacted with incredulity.

– Ch. 63

Under standard literary convention... the enemy wasn't supposed to look over what you'd done, sabotage the magic items you'd handed out, and then send out a troll rendered undetectable by some means the heroes couldn't figure out even after the fact, so that you might as well have not defended yourself at all. In a book, the point-of-view usually stayed on the main characters. Having the enemy just bypass all the protagonists' work, as a result of planning and actions taken out of literary sight, would be a diabolus ex machina, and dramatically unsatisfying.

But in real life the enemy would think that they were the main character, and they would also be clever, and think things through in advance, even if you didn't see them do it. That was why everything about this felt so disjointed, with parts unexplained and seemingly inexplicable.

– Ch. 94

"You may think that a grade of Dreadful... is not fair. That Miss Granger was faced with a test... for which her lessons... had not prepared her. That she was not told... that the exam was coming on that day."

The Defense Professor drew in a shaking breath.

"Such is realism," said Professor Quirrell.

– Ch. 103

Recalling finewbs's coordinated saturation bombing strategy, if the goal is to maximize the total best-guess probability of the set of scenarios covered by at least one solution, this means crafting and posting diverse solutions which handle as wide a diversity of conjunctions of pessimistic assumptions as possible. This would be helped by having a list of pessimistic assumptions.

(It also may be helped by having a reasonable source of probabilities of scenarios, such as HPMOR predictions on PredictionBook. Also: in an adversarial context, the truth of pessimistic assumptions is correlated.)

I'm so confused about the wand. Why does Harry still have the wand? Obviously Voldemort should have demanded that Harry drop the wand before giving him 60 seconds to speak.

Okay, so far as I can see, this is a relatively new avenue of attack, but I haven't got a clear idea yet.

Firstly, assuming Harry can tell LV about some power he knows not (does simple knowledge count as a power? Harry could explain calculus or imaginary numbers real quick...), who do we save? One presumably banned option is to ask for Harry Potter (or Tom M. Riddle) to be saved. Who else is there? Obvious suggestions like Mad-Eye, McGonagall and others don't actually help Harry in his present situation as far as I can tell. Dumbledore?

Secondly, is there any traction in playing the fact that Harry Potter is... well, not the character we're calling Harry Potter? In Ch. 74 'Harry' actually summons Harry Potter (the fake ritual). I suppose the fact that Dr. Seuss wrote some of it means that it was indeed a fake ritual, so we'll call this this thread's crackpot theory. A similar theme is whether by being Tom Riddle, Harry can enter the horcrux system. I put very low odds on him being able to defeat LV from there, but he might be able to reincarnate in a more powerful wizard at least.

Thirdly, we have powers LV knows not. Partial transfiguration... well a number of suggestions have already been suggested involving this so I'll leave it. I will mention that the fact time-turners are safe seems to imply that anti-matter based ideas simply won't work for some unknown reason, but diamond bullets seem reasonable if you can find transfiguration material such as your own skin / Hufflepuff bones.

Any thoughts on this? How much of this (other than the horcrux thing) has already been mentioned?

I posted a longer form of this as a review / solution. Here's a condensed version:

Partial Transfiguration works through a deep understanding of physics. It allows Harry to to create any physically valid state of the universe, as long as he can hold it in his mind.

What this means is that you don't need to Transfigure a gun in order to fire a bullet. You can just Transfigure a bullet in the state of having been fired.

This is what the ability to Transfigure any physically valid configuration really means. You don't need to make a bulky laser weapon. Just make a laser pulse: an arbitrary amount of high-energy photons, aimed in the right direction. Instead of a shaped explosive charge, make a shaped explosion. Instead of antimatter, make gamma rays. Instead of a black hole, dangerous to everybody near it, make a bunch of gravitons and aim them at your enemy.

So given all that, how should Harry kill his enemies?

Lasers are messy weapons. Even black robes are reflective in some wavelengths. Use too much energy and you'll get a fireball back in your face. Release the energy too quickly and it will create an explosion instead of steadily boiling away your target.

Kinetic energy is safer. Transfigure a set of diamond missiles-in-flight, one aimed at each Death Eaters and one also for Voldemort, who is conveniently floating behind them. Giving them a speed of, oh, 0.005c should do nicely. They should be as large as possible - in order to leave large holes - but, since the difficulty and length of Transfiguration scales with the size of the target form, they will be flat and thin: head-sized and a millimeter thick, lying on the ground in front of Harry until the moment when, Transfiguration completed, they instantaneously acquire the forward velocity (and some angular momentum) that will have them impacting the Death Eaters' masks a few microseconds later. The slight layer of air turned into plasma carried in front of them will serve as a nice bonus.

Transfiguring the ground in front of Harry, if possible, is the best solution. Lacking that, pieces of Harry's legs will serve. Since Transfiguration can change the size and mass of the subject, the resulting wounds need not be deep.

If Transfiguration scales with the diameter of the target form, rather than its volume, we will reluctantly use much smaller bullets. A thousand diamond squares, one centimeter across and a millimeter thick, will form a sheet 31 centimeters on a side: much smaller than a car battery. An average of 26 .40 caliber bullets per head should be sufficient to the task.