What was Sephiroth in disc 1?
I remember a popular debate in the first few years after FFVII came out was what exactly you were chasing during disc 1, when the real Sephiroth was trapped in solid mako. Was it a clone? Was it a ghostly image of the real Sephiroth? Was it Jenova?
None of these answers seemed to adequately explain everything that went on during disc 1. IIRC, the Sephiroth you chased seemed to be able to throw Jenova at you whenever we felt like, was able to float and disappear through walls (as in the Temple of the Ancients), but was also seen with a number on his hand (by Dio at the Gold Saucer). Which tells us... a whole lot of contradictory nothing.
So what do you think Cloud and his posse were tailing for most of the game?