Sirius Black was been nineteen at the time, when Regulus had died.
He couldn't quite explain it, when he had rolled and flipped over and stangled with his sheets. He just knew something had gone horrendously peaceful. So peaceful he couldn't sleep. Too peaceful. Like
a body going still. A body going still as a result of the death curse, with no further pain.
Why he didn't save him, insist more he take him with him, encourage him to ask more questions. Take something with him to cling onto, leave more of himself behind. Sirius couldn't answer.
Sirius has always known he was selfish, he has never had a problem admitting to it either. It is simply the way he is. Was born, and raised. He guesses this is just another punishment for putting himself
first, another slap to the burning skin right under his eye between his ear and nose.
Regulus, on the other hand, while never selfless, tended to put certain things above himself. The result of being a second-born, he'd always joke. Always the thinker too, that one. Always ready for
all that threatens to come. A perfect balance to Sirius' reckless and unexpected nature.
Which makes it all a bit more surprising, when the idiot dies so quickly. At eighteen, fresh out of Hogwarts, with nothing behind and a full life ahead. He was supposed to have an entire future before
him, he did. Lord Regulus Black, an arrogant git. But living and alivingly ignorant, just as he'd always wanted.
Even so, Sirius knows. Can almost feel it. That Regulus Black died for his own cause, in his own conditions.
That, made Sirius further resent his younger brother.
Suicide, or the equivalent of, it was.
He can say he called it, saw it coming. Told you you aren't bloody built for this. Fucker.
Regulus had died a coward's death, yet Sirius teared for a lion's blood.