You never asked for this.
You had such a bright future ahead of you. Being an Advanced Placement Student meant that you were on the fast track to bigger and better things---the world was your oyster! You could have gone on to any school you wanted, done anything you desired. You were going to be a rising star and a future leader. In fact, we all know you would have made an excellent President of the United States---the first Asian American President, no less!
That is until you were chosen to be a Prophet of the Lord. The burden was frightening and overwhelming. We watched you flee in abject terror from Sam---all the while clutching the important Leviathan Tablet---even if you didn't know why you wouldn't let it go. You were to figure out how to stop the threat of Dick Roman---and you did. You told the Winchesters what the secret to his defeat was.
That should have been the end of your Prophet duties, but unfortunately so many others had other things in mind for you.
Through it all, we were privileged to witness the growth of a frightened young man into a hero. You didn't choose to be a Prophet, and you didn't want it, but you made do with what you were given. We were astounded by your resourcefulness to escape from Crowley's clutches and to evade him for months. Our hearts hurt for you when we saw your grief at your girlfriend's vicious murder and your concern for your mother.
We saw how adaptable you were---how you were a survivor.
You truly became a hero, however, when we saw you go toe to toe with Crowley, telling him flat out that you wouldn't tell him what the last Trial was---all with the courage and swagger we knew was in you the moment we first saw you. You knew you were risking pain or death. You knew that Crowley was no one to mess with, but you did it anyways.
And after you were reunited with Sam and Dean, we saw you become more than just an Advanced Placement Student turned Prophet of the Lord.
We witnessed you become Family. Sam and Dean's Family. Our Family. We smiled big when you were proclaimed a Winchester, brought into the fold, doing your part to decipher the Angel Tablet and reverse what Metatron has done.
When called upon to help the brothers in other ways, we saw you react with greatness. Your quick thinking got the Winchesters into a crime scene they wouldn't have otherwise, and it's all because you showed everyone the hero you really are. You knew what needed to be said and done and you went ahead and did it.
Your exit makes us sadder than I think you'll ever know. Our hearts are broken that you'll no longer be there to shoot arrows waywardly at the balcony. We'll miss seeing the comfortable ease with which you worked with Sam on research or how you and Dean had great chats. We'll miss seeing our Prophet get excited about the latest breakthrough on the Tablet, or explain things much too quickly for Sam and Dean to understand.
Most of all, we'll miss the hero that you are.
To us, you'll forever be our Kevin Freakin' Solo. Always.