Quote Originally Posted by Alberel View Post
We don't actually have conclusive proof that a primal cannot be summoned multiple times at once... If we take the whole concept of King Moggle Mog for example, since he is just a myth made manifest through belief there had to be some point that he was simply created from nothing. There was no 'soul' in the aetherial stream to summon. To be honest we don't even know if the primals have persistent souls and memories between summonings. If Garuda were summoned by a group of Ixal, and then another group of Ixal tried to summon Garuda in a different location, unaware that others had summoned her, there is nothing in the lore so far to suggest they would be unable to do so.
Ultima Weapon traps the primals and prevents them from being summoned again.

Same goes for the seal from mor dhona and Dalamud trapping Bahamut, all Allagan techs were aimed so that primals couldn't be summoned again.