Summary: this is my interpretation of what's going through older Valerie's head just before that scene in TUE. It's my first time writing in any POV other than the normal one, so be kind!
Disclaimer: I do not own Danny Phantom!
Lying in a pile of rubble for who-knows-how-long really gives one time to think. As I stay here, nearly as invisible and intangible as the nosferatu I seek to eliminate from the face of either world, I think about why he became the way he did. Why he abandoned the path of the ultimate hero and became the ultimate enemy.
Every ghost has a purpose, Valerie. Every single one. If they didn't why would they have come back as a ghost in the first place? Mr. Masters' words reverberate inside my head as I contemplate my foe. A foe whom I'd had feelings for, but that's not the point.
Or is it?
Every time he attacked our town in the last ten years, he'd always took the time out to find me. It would have been sweet of him had he not been trying to annihilate me. As if his sole purpose in life (or afterlife, if you want to get technical) was to seek me out and destroy me.
Every ghost has a purpose…
But why me? That one I can answer easily. After the explosion that killed his family, his best friend, and his girlfriend, he came to me. He came to me knowing that I'd made a vow to hunt half of him down, came to me with a secret greater than life itself; the secret of his half-life. And I threw it in his face. I overreacted and shot at him, and he fled. And when he returned he'd forsaken his humanity and became what we'd mislabeled him as all along-pure evil. My actions caused him to become that…that…monster. My actions unleashed a manifestation of the ultimate evil on the town I grew up in. My actions…
Every single one…
So an I responsible, even if not directly? Am I the one who caused the chain of events that led to the wasteland around me? Am I the one who's responsible?
"I don't know…but I get the feeling I'm the one who's responsible…"
Him. Even if I did start the sequence of events, that doesn't make him scot-free of the lives and property whose existence he ended during his ten-year rampage.
"You got that right, ghost!" I shouted as I leapt out of my hiding place and fired my ecto-bazooka at the one who had caused all this. The one who had ravaged Amity Park mere months after saving it from the Ghost King. The one who destroyed so many homes and innocent lives. The one who used to call himself Danny Phantom.