Saving the World and Possibly Myself

Hunter Winchester has spent her entire life saving people and hunting things. The family business. Now out of the family business, she thinks her days of saving the world are over. Fury and Coulson have a different idea in mind.

This is a bit of a Supernatural and Avengers crossover. However, you don't need to know anything about spn because it will be mostly Avengers and the spn stuff will be explained when it comes up. Also starts off more Agents of Shield rather than avengers, but it'll get there.