That's not really accurate at all, though.
  • Chaos is just a powered-up version of Garland, you see at the beginning of FFI.
  • Dark Cloud's existence is alluded to in FFIII's text and appears at the end of the second-to-last dungeon, not right before you fight it.
  • Ultimecia is talked of a lot throughout FFVIIII's plot and makes frequent appearances. The only reason you don't see her directly is because she's possessing the bodies of other sorceresses.