I just got done playing this part in the game, and it matches perfectly, so if this isn't it, then I give up.

  • What they throw back wouldn't scratch me I can take this stuff all day.


In the "Cloud's Past" section of the game, Sephiroth seems untuchable, and every attack does 0 damage.

  • With a crack I'm back in there beating dragons on my way,


You find a dragon at the beginning of "Cloud's Past."

  • Then am gone with a whoosh noone knows just where I go,


After the first incident at the reactor, Sephiroth mysteriously disappears.

  • Ratatata they be falling one by one within this town.


After Cloud finds Sephiroth, he burns the town and kills everyone who survived the fire.


Well, that's all I got right now, and I'm done guessing.