Liked the background information and the description of Harry's symptoms at the beginning. Even though you didn't expound on it much, I could feel Harry's loneliness. The articles in the Quibbler's classifieds were amusing.
They were clever, sharp-eyed and sharp-beaked. They were like avian versions of himself. This made me smile.
Liked the description of the magical diagnostic spells Snape used and his theory about the curse. Harry's illness is quite terrifying. I liked the theory that Harry felt it was just his time to die, that he was living on borrowed time. I played with that idea before, in an unpublished fic I wrote. Maybe one day I will finish and post it.
I also liked the description of the spell ball creation, the symbols and their lights. So different from the diagnostic spells but just as interesting.
I like that you manage to mention that Albus was gay. :) Hermione and Luna were great! I liked the bonding ceremony. It was very earthly.
Severus was truly at a changing point in his life with the bonding, wasn't he? He was willing to give up a lot to help Harry but at the same time, he would be finding his true self. I like the psudeonym he chose for himself. It suits him perfectly. But now, with the bonding, there was no more two-faced antics, no past and future; just himself and the present. I could see where he would be more nervous than Harry. Though they are both making big changes in their life.
I liked all the magic involved, including the workings of the bond. The first sex between them was sweet. I hated that the second was such a chore. But now that it's all over, I'm sure things will improve. This was a very enjoyable read!