God of War: Ghost of Sparta

Story related, can’t be missed. This is located in Suicide Bluffs, near the end of the game. You'll have to climb up the wall that you've landed on and as you're climbing you'll need to break the rocks on the ceiling. Continue climbing as fast as possible and once you climbed up the ledge run towards Deimos and press the button, then repeatedly press the button, and finally, repeatedly press both the + buttons to save Deimos. He'll now join you for the final fight against Thanatos, armed with your Arms of Sparta. Save your game at the save point and follow to face the final Boss. Your trophy will eventually unlock after the cut-scene.