It was placed in the Shinra military school setting, Cloud was either sent back in time or just mentally a lot older, Aeris was mean to him, Sephiroth and Zack mistrusted him until they saw him collapse and Aeris started hurting him,Reno was his classmate/friend and always followed him around. I think Vincent was his teacher in something. I think Cloud was immortal and in the later chapters they found out the only way he could be killed was by fire/ burning all his cells at once. Also, when Cloud is taking his exams he has to fill in the wrong answers on purpose so he doesn't 100% it and look suspicious.
There was one line where Reno said: Why do you walk when you could use a car. And Cloud said something akin to "because I can see what I'm fighting for".
Yeah, my memory of this fic is jumbled all over the place but I remember it was a good read, very long and well written, I just can't seem to find it anywhere so if anyone knows which one it is or has it archived I would be eternally grateful.