Disclaimer: Not mine in any way shape or form - no profit for me from this!
My first story in years - sorry if it is terrible!
Sirius Black was always going to be important in the war – it was something that Albus Dumbledore instantly knew when looking at the latest group of first years huddling together in the middle of Hogwarts main hall. He was a young boy who had within him all the potential in the world to be a guiding beacon in the war that surrounded them everyday, but he could equally become a great enemy of the side of good once he was trained and taught how to grasp his full power.
Being a Black, Sirius would have been easy to write off as inherently on the side of the dark Lord, but something about the skinny black haired child held Dumbledore interest far longer than any other child – save one tawny haired boy who held the same dual potential as Sirius, however he was less fearful of the second as he was able to keep his darkness a secret.
As Sirius slowly stepped up to the hat and sat on the stool, Dumbledore held his breath knowing in that instant the boys future would be decided. Would he stand for all that was right with the world or would he fall into darkness, as the Hat made the decision and allowed all to know Albus was the first to start clapping as the startled boy made his way shakily towards his new family and brighter destiny.
When asked years later Albus would admit there were only two people he was disappointed in truly. The dark lord himself who whilst containing the essence of darkness could have changed – but even more so was Sirius who allowed himself to be pulled back to his families way betraying all who had trust in him.