Eidolons are the returning eidolons from the previous Final Fantasies. Only summoners from the Madain Sari are allowed to summon the Eidolons. Eiko and Dagger (or Garnet) are the two of the usable summoners. Summoners has acquired the ability of the curative magic of Gaia.
The legendary summoners resides at Madain Sari, which is located in the Lost Continent of Gaia. Within the village, there is an Eidolon Wall.