The CoE formations are a 9 square layout that contains formations that are unlocked as you level up your character.
Begining with the basic formation. Players can choose the placement of their eidolans within the unlocked squares.
Eidolans can be deployed by clicking the formation edit bu
Players can choose to select by infernal, glacial and vital Also 3, 4 and 5 star or by def, attack and commander, to help make selecting the right eidolans a lot easier