SIRIUS BLACK
Sirius had once idolized Bellatrix. He had believed the blood purity, that Muggleborns and Muggles were scum, that half-breeds were filth.
When Andromeda had run away, he had disowned her like everyone else. When he saw her at school that September with Ted he realized she was happy, something she hadn't been at home. That's when his thoughts began to change.
James finished the process. He didn't care that Sirius was a Black in Gryffindor like everyone else. James told him these things didn't define him, only the things Sirius did. Then Sirius "re-owned" Andromeda and forgot his other cousins.
Sirius had fallen for Savannah the first time he saw her. She was everything he had thought a girl should be. It was the only secret Regulus alone knew.
Sirius had hated Remus until James had threatened to stop being his friend…and he discovered Remus threw a mean punch.
Sirius was always the one who treated Remus the worst, even though he was the first one to see him after a full moon, even after he suggested that James, Peter and himself should become Animagi to help him. He always wondered if that's why it was so easy to think Remus was the spy. He never forgave himself for that. He felt like a traitor because of those thoughts.
Sirius had married Savannah in secret. Only James, Lily, Remus, Mary, Peter, Alice and Frank knew about it. The Order found out when Patrick was born two years later.
Sirius was laughing when they took him to Azkaban, not because he knew what was coming, but because everything he had done was in vain. Everyone he cared about, James, Lily, Savannah, Patrick, were all dead, Remus hated him and Peter, stupid, clumsy, unconfident Peter had outsmarted them all. And Sirius was going to pay for it.
As much as Sirius saw James and Lily's blank faces in his dreams and Remus sitting alone in a cold room on the brick walls of his cell, Sirius was more tormented by Regulus's death. He couldn't help but feel like he had failed his brother that he had given up too soon.
He knew Remus was falling in love with her. He could see it in his friend's eye. Sirius knew Andromeda wouldn't be thrilled, but he felt it was about time something went right for Remus and what better way than to woo the girl, even if it was his "Pretty Princess Dora."