Who Zack Was
The Remake trilogy tells Cloud's story with the context of who he was trying to be. Crisis Core tells you who that was, and why. Zack is everything Cloud isn't at the start of Remake: open, enthusiastic, at ease with himself. Watching that erode slowly across the game is the story. His relationship with Aerith is the emotional spine. It's quieter and more ordinary than her dynamic with Cloud, they're just two young people who like each other, and that ordinariness makes what comes later hit harder. Reunion lets you feel the weight of it.
