I've re-read it and I love it even more now. Antonin's story is so believable. You imbue him with a wonderful, convincing russian-ness, and give him enough tragedy and anger to make his eventual decision to join the Death Eaters almost inevitable. Almost. Because Flitwick gives him hope and other possibilities: a world in which he belonged to Filius and Filius to him might well turn out to be one in which he could live after all. But then Filius takes that hope away again.
I love how complex both of the characters are. Neither is entirely good or bad and -- in the end -- it is Filius (who never stops being as kind and bright as we know him in canon) who puts his career before his love and thus destroys both of their happinesses.
Fred's death is one of the saddest in canon for me. Yet, you had me so invested in Antonin that it became peripheral. Amamzing work!
I love Flitwick and it's great to learn more about him. I didn't know that I needed more on Dolohov until you gave it to me.