I don't understand why showing the thinking of the DM/Author is important for this problem. To me it feels sufficient to show the thinking of the characters alone?

I'm too obsessed with antimatter

A one-atom wide line of antimatter along his skin, down through his shoes, through the ground, and into Voldemort's brain, where you make a microgram lump. Still doesn't kill him, precisely, but it should at least make him mad

If I were Snape, I would use a gas. Something which becomes hazardous after a certain time. Or merely change the nitrogen/oxygen balance after a certain time.

There are two prophecies at work here that I don't understand, which even now have to be vital to the ending

• HE IS HERE. THE ONE WHO WILL TEAR APART THE VERY STARS IN HEAVEN. HE IS HERE. HE IS THE END OF THE WORLD.
• Thrayen beyn Peverlas soona ahnd thrih heera toal thissoom Dath bey yewoonen

I really don't get why Quirrel is doing this knowing the prophecy of the stars.

Also, the transfiguration Harry is doing is an obvious hint as to the antimatter weapon ending.

Assuming that the Mirror of Erised works the same, Bellatrix is the obvious wielder

Weather's looking good

Yes.

Who is Sirius? Fudge!

• It is well known that Sirius was replaced before he went to prison (the repeated "I'm not serious", the phoenix screaming particularly loudly at one particular door)
• Fudge was present at the capture of Sirius, and made Sirius go to Azkaban without a trial- which means Fudge needs to keep the person in Sirius's body locked up for some reason.
• Sirius can switch bodies somehow (Someone who looks like Sirius enough to fool everyone else is in prison)
• Fudge is under the thumb of the Malfoys- why? He's using them for support, but there has to be a reason why they can dominate him completely- and being able to expose him as a death eater does that.
• Harry predicts that Evil!Pettigrew would be with the Malfoys- or in the caribbean? Why not predict the caribbean first? Because Evil!Sirius is with the Malfoys.
• Meta-dramatic point: Harry has never talked to Fudge. Every time he has a chance to talk to him, like during Harry Potter Day, he hasn't- even during the trial, Fudge never says anything.