SLYTHERIN: “‘With great power must come great responsibility.’ That’s one way to go. With great power also comes the ability to rain down hell on those who prey on the weak, people who couldn’t fight the monsters.” -Christopher Yost (Kaine Parker: Scarlet Spider Vol 2 #12.1)
Honestly, the biggest plot hole in the entire Harry Potter franchise doesn’t have anything to do with temporal shenanigans or magical mechanics or even basic plotting. The biggest hole is this: how the hell did Dumbledore talk McGonagall into going along with his plans for Harry?
I mean, it’s such an obvious Needlessly Complex Supervillain Scheme if you’re reasonably in the know - which she was - and she’s not just smart, but genre-savvy, so there’s no way she could have failed to piece it together. And we know enough of her personality to know that she would have found the whole idea abhorrent even in principle, let alone once the casualties started piling up.
So what could he possibly have said to her to convince her that letting him play Risk with children’s lives beat every possible alternative?