This is the award for beating the second stage. It's unmissable. The stage ends with a great fight against Mistral. Honestly it's not a very difficult fight, the big trick in the fight is to kill the dwarf gecko as fast as possible. This will also help you earn the "Looking out for the little guy trophy" Beyond that the fight turns into a very normal fight, make sure to parry her attacks and then beat her down when you get an opening. If you practiced the parry system, it should a be a fast but satisfying fight.