I like it! Just to expand the possibilities, I'll go a different direction:

Years ago, I was a shy naive girl that just wanted you attention, and maybe, your love. I didn't get either. I served you hope, promise, and cookies. You returned a plate of apathy and dismissal. This is what you do, Peter. I also realized I wasn't the first you did this to. I was just the latest in a long line of people that loved you, that you pushed away and destroyed. Despite the ideas of heroics and selflessness you wrap yourself in, you are quite the opposite. Your teenage selfishness killed your Uncle Ben. Just a few years later, a man took you under his wing like his own son and because of you, he became a villain the Green Goblin and you killed him too. Another poor man that showed you love, Dr. Otto Octavius, became the villain Doctor Octopus because of you. You couldn't stop at destroying father figures. As young adult you had to betray your best friend and Harry Osborne became evil.

I suppose I should thank you. You taught me who you were, and I learned my purpose. I need to stop you from creating more villains in your wake. The world can't take the evil you create. Your arrogance and hubris must stop. This sacred duty falls to me to destroy you.

Peter, I suppose I should introduce myself, even though we've certainly met before. You knew me before as Ursula. However now I am Oblivion. It is my fervent hope that you will finally join me in becoming nothingness.