This is an incredibly beautiful story. The writing style is superb and I just adored your subject matter. I love the idea of them working together and the whole department, and I particularly love Snape's new cause. It's brilliant, it's perfect, it's completely enthralling. I liked how the teacher explained about violent, chaotic adults-- how not everyone who grew up in that environment ends up like that, but that most people who do grew up like that. Heartbreaking and painful and so vital for us to understand.
Viktor knew something about how survivors could be so tough that they were brittle. He also understood why Harry would pursue Snape anyway. It was nothing either of them could help. Harry must know why Snape avoided him and Snape must know why Harry sought reconciliation, yet they could not stop. Someday they would be old men like his uncles, almost whole, almost recovered, but not quite. This is beautiful-- the style, the wording, and the subject matter. A hat trick of lovely, if you will. :)
The bit with Viktor grabbing the orange push broom and flying it-- oh, that was marvelous! *claps excitedly* I let out a gasp of giggly shock at that-- so much fun! I just loved it. And I never thought I would buy Snape being compared to a cute little kitten but what a perfect ending.