Avada Kedavra – It's not the end. Not really. Not for most… Nor for anybody, when it comes down to it. For those who speak it, it's a continuation of normal life. For those it hits, it's still a continuation of life – perhaps not normal life, but still life. And whether by light means or, indeed more commonly by dark means, succession of Avada Kedavra is not unknown. Such has been seen in the story of the boy who lived.
But alas, this isn't all common knowledge to the common wizard. Those affected have no means of communication with those they knew in their normal life simply because… their lives just aren't normal to them anymore. Sure, the body is there, dead as dead can be. Such cases make rehabilitating more difficult for those affected, but in the case of Sirius Black… well, we all know his body was also lost in the Death Chamber. Those black curtains can be such life-savers.
The world, or indeed the magical world, it seems, has an infinite supply of dementors. It's amazing that none of the major names in the wizarding world have never realized that the ratio of people killed to the number of dementors know to exist is almost one-to-one. Well… maybe not "none"…
On any other day, a "new" dementor can be seen floating around Azkaban. Not because they look different at all – gosh, they all look the same – but if one were to count them all up, a change would be discernable. But to see a floating body appear around Azkaban, this proves to be slightly more brow-raising in the prison. This is made even more significant by the recognition of the body, a previous inmate.
Of course, the inmates in Azkaban don't know that Sirius Black has been killed by Bellatrix, they can't even tell that he's not quite "alive" either. They don't notice their fellow inmates drop dead after an embrace from their long-gone friend, they're just happy to see him – and still free no less.
But alas, Sirius is not free. It doesn't take a department of mysteries' analyst to notice that Sirius' cloak resembles that of a dementor. The ethereal feel of his tears dripping from his cheeks as he gives them their last kiss, or is that the rain?
Sirius performs the dementor's kiss to bring himself back to life, or indeed to keep living as he is. It isn't a choice. It isn't a pleasuring or painful experience. It's just a matter of life, it is his life.
It isn't often that a dementor becomes themselves again. Indeed, it has never actually happened before. This is a fact. It makes it even more unlikely that Sirius, being one of few to keep their own form into this (to be quite frank) demented life, is even less likely to become himself again. Not without intervention. And who is there to intervene when you're floating around Azkaban?
Life indeed does continue after Avada Kedavra. The killer continues, if only for a short while. The victim's family continues, grieves, mourns and moves on. The victim also, although not commonly known, continues, kissing those worthless to others, perhaps even their killers. Not out of love or hate, or any emotion at all - as dementors have no emotion, only an instinct and a drive to feed, to kiss. To stay in existence.
