Harry woke with a start. He looked over, but the strange man was still sitting there. He looked up, and saw the kind witch with her cart of treats. He nudged Ron to wakefulness, and they both bought several handfuls of candy each. After thanking the lady, they discussed possible explanations for Mr. Oscuros and why he was on the train.
"Could he be the new Defense Against the Dark Arts teacher?"
"No way. He's probably a new sixth year."
"Do they even accept new sixth years? Anyway, he looks like a teacher..."
"Well, why does his scabbard say Auror?"
"Maybe it was a joke or something. 'Sides, who says it's a sword in there?"
"What else could it be?"
"Fine. Why does he have a sword if he's a wizard?"
Woken up by Harry and Ron, and tired of listening to the two arguing, Hermione finally broke in with, "Hey! We'll find out soon. We're almost to Hogwarts."
The boy - or man? - was still sleeping when the students climbed off the train. Leaving him behind, the trio of Harry, Ron, and Hermione set out for Hogwarts Castle. As he walked, Harry tried to find his sixth year crush, Cho Chang, but didn't see her.
As they walked into the Great Hall for the Sorting of the First Years, Harry's thoughts went back to the violet-haired man - boy? - on the train. Looking around, he could see Cho now, but where was that man? Harry decided to forget it for now. He watched the Sorting, remembering when he was Sorted 5 years ago - the hat 's voice in his ear, the quiet pressure, the hat calling out, "GRIFFYNDOR!" - and realized that Sorting was over and Professor Dumbledore was saying something.
"As you all know by now, Lord Voldemort - " Professor Dumbledore got a good gasp at that " - is back. The Ministry doesn't believe it and has not given us any help. However, we do have - " he waved a hand towards the end of the High Table " - one friendly face. I'd like you to welcome your new Defense Against the Dark Arts teacher, Professor Oscuros. Let the feast begin!"
Standing there, at the High Table, was the boy - no, he must be a man to be a teacher, a MAN - from the train.