The bug is that Rippler affects all statuses, even the "not named in-game" ones which were not meant to. Rippler is not supposed to affect Magitek, Petrify, KO, Critical, Dance, Rage, Frozen, Trance, Chanting, Hidden, or Interceptor Guard, but does anyway. This means that Shadow can lose Interceptor permanently, and any character could use a Desperation Attack even if their HP isn't critical. There is a bugfix patch that players can use to fix it on the SNES version.