Originally Posted by
Enkidoh
Because that's actually not how the Limit Break system here is designed - a Limit Break is based on party role, not your own class/Job, hence the animations are shared. When a Limit Break goes off it's not just the person who used the Limit Break doing the effect - the whole party is 'lending their power' so to speak to accomplish it.
As for the Buster Sword animation in the DD Limit Break, that can easily be handwaved away by saying 'it's aetherial' and a manifestation of the character's will or something. Really, you're over-analyzing what is simply a little bit of fanservice, an easter egg. Nothing more.
This argument was debated to death back on the Beta forum (I still remember the big who-ha which broke out there when the 'Crystal's Call' trailer showed it for the first time) so I really don't think going on about it at this point is really going to solve anything.