The second part of the story is "Harry Potter and the Confirmed Critical". In said part's climax, Hermione decapitates the basilisk with the Sword of Gryffindor, as a reference to Jabberwocky. D&D adopted said poem's vorpal blade into a powerful enchantment that decapitates and kills almost any monster on a confirmed critical, so it is effectively a way of saying that Hermione scored a confirmed critical with it, as a subtle Title Drop.
Also? Snickersnack.
The second year the story is significantly shorter than the first, even though it has more side stories such as police. Why is this? Because Milo is possessed by Riddle and has gaps in his memory. He performed as many actions as first year but forgot many of them, leaving his contribution to the story shorter.
Why did the ritual summon Milo "instead of the Great Archmage, the enigmatic Ninth of Eight"? Well, it didn't summon Milo specifically. It summoned his familiar, who shared the same name as the person they wanted. Milo just got pulled along for the ride since he and Mordenkainen's souls are linked.
And why did the ritual summon a random Wizard's familiar instead of the "Great Archmage, the enigmatic Ninth of Eight"? Because Lucius cheated. He gave a secret he had never told a living soul, that is true, but it was an irrelevant secret. So the ritual gave him Mordenkainen, that is true, but not the one he was looking for.
Why does Milo dislike Bards so much more than any other class? He is/can be envious of other full casters, and dismissive of most other classes as “use-impaired”, but Bards seem to earn his unmitigated and unexplained ire. Why? Simple: Sibling rivalry.
Why does Milo know how to play chess earlier on in the story, but then in the dueling club think chess plays completely different? The earlier instances were off screen, handled during a time skip and thus not by his conscious mind.
Bode's description of how the department will kill Milo if he turns out to be non-human ends with Milo being disapparated into the sun. Then Bode says, "In my experience, that'll kill anything short of a Dementor." What exactly does it take to kill a Dementor?
For the record, the canon answer to this is that Dementors can't be killed. But given the author's professed fondness for Harry Potter and the Methods of Rationality, the True Patronus may exist in this story.
