-( Story related, cannot be missed )-
After finishing Dark Side of the Moon with Natalya, you'll end up facing off Milenkov directly. The goal here is to simply break his armor and then dismantle him. To do so, shoot at him with your Disintegrator, blast at him with the Ion Detonator, or even try and Meteor him up. Either way, this fight is the simplest of the bosses. Strafe when he shoots his green energy balls at you and move about when he launches missiles with his weird tail and that's all he has as attacks. You won't get this trophy until after the cutscenes and credits though, as once they are done you'll go back to free-roam.