Harry Potter pov)
I slash my wand but the curse is deflected away by my target. Severus Snape, a man I watched almost die, if I hadn't had that vial of phoenix tears in my pocket he surely would have, it's been many years since the war, the man is the bravest one I know, also the strongest.
Of course I could not resist getting lessons, when I saved him he had only this to say "Potter, I must say as much as it irks me to admit I am in your debt, I shall grant you a favor, any one thing in my power." I had already seen the memories by the time he had recovered, I thought for a few moments.
"Severus Snape, you are an unbearable arsehole, but you're one I'd like to be friends with, my one request is at least once a week I'd like to talk to you over a drink or meal."
That day wasn't the day everything changed, but it was the start of the changes. Most certainly, it was rocky at first but he had information I wanted, he knew my mom early in her life a way nobody else had. So I brought her up one fateful day and his eyes lit up with excitement.
"I wasn't aware you wanted to know about her, you being so much like your father?" His words to me were what caused me to say this in response, this is what truly made all the difference to this bitter man.
"I hate what he did so much, James may be my father but I wish it were someone else, he loved me dearly but I know now he was not a good man to you, I know you now far better than I do him, I hate what he did to you Severus, I personally wish I took more after my mother."
Severus changed that day, for the better I'm certain because my next words to him were, "I forgive you Severus, I'm sure she would too, she may have been unwilling to talk to you back in your sixth year. But I'm certain by the time she had died she would have talked to you and forgiven you."
He smiled, something out of character for him at the time, his eyes watered something that surely even less common for the man. He said to me "Thank you." After that day we talked about Lily every time we met for weeks, eventually Severus had exhausted his stories of her, but by then we were fairly close so I decided to ask about other things.
That was what led to the duel, he was teaching me what he knew in the hopes of helping me on my journey to finally teach Defense Against the Dark Arts.
Suddenly I'm wrenched from my thoughts as a Difindo is tossed my way, instead of doing what Severus does with his grace and finesse. I simply project an angled shield to toss it back instead of manually redirecting it.
Severus simply side steps, he says another spell in an even voice, he doesn't need to but it's for my benefit, to help me recognize spells in case someone were to cast silently. "ego caluror." Based on the Latin that's a horrid one I don't recognize it but it can't be good, I quickly try to think of a counter it's too close to dodge.
"peperitgelu." I cold mist absorbs the spell, luckily my counter worked, I push the cold Frost towards Snape, he does something that shocks me to my core. He manages to transfigure the Frosty mist into spikes of ice and Banishes them at me. I know he said he would switch up his style but I never thought he meant to swap school of magic, I thought he would simply use different chains.
I conjure a steel shield and the ice shatters against it, I banish it at Snape.
Suddenly I see a flash of red and then nothing.
I woke up on the stone floor. "Good try Harry but not good enough, not many are, you certainly should have the qualifications for the job."
I smile brightly, today was a good day I have hope that tomorrow will also be good.