DISCLAIMER: none of this is mine
They call me a monster you know; a callous heartless traitorous monster and while they blame whoever they can they forget that once I was just another fighter, just like them but in their defence He had just been defeated and they didn't want to taint that with finding more death-eaters like they were supposed to, they were happy, it was over! And it was over, Voldemort's life was over, Lily's life was over, James' life was over, Gideon, Fabien, Marlene, Dorcas, Caradoc even Regulas although I'm not sure how many others mourn for him – their lives were all over already, Frank and Alice – their lives were over a few days later, me – my life ended the next day as well; whether or not I'm dead or alive, imprisoned or free, I certainly do not have a life for that was extinguished on the 31st of October 1981.
They call me a monster and do you know their right because if I could I'd go back to that time and I wouldn't make the mistake of trusting that rat oh no, I'd let them live and at the same time we'd be letting Voldemort live and live to slaughter millions. So those people are right; I am a monster because if I could I would trade thousands of people for two lives. For Lily and James I would sacrifice the world even if in doing so I would also kill off any and all chance I had of being their friend again because the kind of callous monster that would sacrifice everything for two people is not the sort of person they would ever be friends with.
I, Sirius Black am a monster. No matter what else they take they can't take that away because they will always remind me of it, even if sometimes monsters can be alright.
And I hope that in my monsterness I have managed to save some lives