Summary: years after advent children, Cloud thinks of Sephiroth.
Memories fade. It's a fact of life that all events that stood out so vividly will bleed away until nothing remains but an array of faded images. Wounds heal, becoming faint scars, barely more tangible then memories. Time passes and friends part ways, the connections are still there drawing the survivors together to celebrate peace or to simply contemplate what could have been.
"I will not become a mere memory." Your final words, a desperate attempt to be more then just another corpse on a wasted battlefield. You spoke the truth though, you can never be a mere memory. A decade or two can pass and the image of your eyes will still burn. The feel of your blade will still be remembered by my body, my scars a map of your anger and resentment.
Your world had crumbled around you, as a consequence you wanted to bring down ours as well. But we fought, the world depended on us and we refused to let you take it with you. That I think, you never understood, we fought not for ourselves but for the countless innocents that your wrath threatened. Knowing I could protect them was what gave me strength, having a home to return to gave me the will to see you to your end.
I hated you and…I pitied you. I felt your pain but could not condone your actions. Now, I'm not sure what I feel. It's been years, and even now when I look back over the memories all I can see is you. I think I understand more now than I did before. Like me you were always alone, you needed something to fill that emptiness. I found Aerith, Tifa, and the others; but all you had was your anger, and Jenova's poison.
Was it the end for you, that battle? Or did you go on into the life stream, your thoughts mixing with others. Your rage and loneliness mix with millions of voices diluting so that even that had left you.
I hope you found your peace, I hope that perhaps somewhere you've finally found happiness that is real and not a lie.