change the prophecy
Regulus Black goes back to Hogwarts a different person.
He's pale and quiet,he jumps with every sudden movement and shrinks in his seat whenever Barty and Evan start to scream fight.
He no longer searches for James or Sirius in the halls.
He no longer responds to Pandora whenever she rants to him whenever she need to.
"Reg?" She says "are you even listening to me?"
"Yeah" He lies and takes a sip of his glass of water "i am"
And that is his life as he goes insane.
At first its nothing.
He's sure its nothing.
But then his leg starts spasming and he's sure there's people standing behind him every hour of every day.
He knew this would happen.
Sirius was free,yes.
But now he was the heir.
And the heir of house of Black always ends up crazy.
"BLACK!"
Regulus speeds up.
He knows that voice.
He loves that voice.