This is one of my favorite examples: It's the conversation that Snape and Alice have right before the May 16 battle, and they touch upon Neville and his choice in December. Snape's tribute to Neville just moved me so deeply (brilliant writing, Denise):

I do not think Neville would begrudge me telling you this: he loves you immensely, but he believes in what we are doing more. His greatest joy was the day you told him what you were doing, and why you were doing it; his greatest pride was the day he was brought into the Order and could see for himself the cause for which you were fighting.

I have never known anyone so thoroughly possessed of the virtues of the Gryffindor, with so few of the vices. I spent years visiting his thoughts regularly, and I can tell you this, with no fear whatsoever that I am making up pretty lies to comfort you: he would not — will not — hold you to blame for what has happened. Not in the least. He would have sacrificed himself a hundred times over to preserve what we are doing, and counted the price a worthwhile one each time.

You have not forgot him. You will not forget him. You will find him, and we will rescue him when it is possible to do so, and we will take care of him for as long as is necessary, and the entire time you must — must — remember this: he loved you enough to give up his self to buy our safety, all of us, and I know him well enough to say that there is no part of him that did not pay the price willingly.

Do not take that choice away from him and count it a sin against your own reckoning. It was his choice, and you must honour it. I say this with the greatest of confidence: to him, not having done so would have been far worse.

You raised a son who was capable of making that hard choice — the right choice — at precisely the right time. Not many would have been able to.

Now consider:

*What a classic example of Alternity inverting canon. In canon, Snape reasoned that if Voldemort had picked Neville instead of Harry, Lily needn't have died. And so Snape hated Neville. And yet in Alternity, Neville is someone he genuinely admires.
*In the same way of canon inversion, instead of a hateful, wounding Snape we get a nurturing, consoling Snape.
*Snape is about to die. He's talking about Neville, but these words can also be considered counsel to Alice about how to think about HIS death.
*Neville is about to sacrifice himself AGAIN. And in this case, he won't even have the mind to make it his own choice--but it is POSSIBLE, he is in the right position, because of the choice he made in December.
*Alice is a leader who is about to lose a LOT of people she cares about. Snape is teaching her how to think about it so that she can do that and still hold onto her sanity.