Aberforth and Sirius are two of my favourite characters, but I'd never have thought of putting them together - and you managed it marvelously. I love your Aberforth voice, gruff but with the pain still on view, and he makes the perfect foil for Sirius.
And gah, Sirius. I hate to think of how starved he must have been for human contact and affection at this point (and I love that this was somewhat mirrored by Aberforth's own emotional state). I thought you dealt with him brilliantly - I loved Aberforth's memories of him as a student and younger man, and the way you tied Sirius to his Padfoot persona was lovely.
A great story - the kind of thing for which I'm so grateful that this fest was created.