Zack Fair plays a prominent role in the Final Fantasy 7 mythos, eventually getting a spin-off/prequel that detailed his life as a 1st class SOLDIER and eventual death, which later led to the events of 1997's Final Fantasy VII. Unfortunately, the prequel was limited to the now-defunct PSP, so a lot of JRPG fans never got a chance to play as Cloud Strife's best friend and the original owner of the Buster Sword.
If we believe the claims of what's believed to be the burner account of a prominent industry figure, this is about to end soon as Square Enix is reportedly set to announce a remaster of 2007's Crisis Core: Final Fantasy VII.
Before we proceed, SPOILER ALERT!
Crisis Core details the events of Zack Fair's life before the start of Final Fantasy 7 as well as its remake. However, the ending of the INTERmission DLC might have "confirmed" what gamers thought of all along: that the remake isn't a simple retelling of the original timeline but the diverging of two separate ones.