Quote Originally Posted by eiko guy
in x if 2 summoners summon the same monster who will it come to and there is no way with all the summoning that an aeon hasnt been called by two summoners at once
In X there are even battles between the same Aeon, like Yuna with Isaaru's but each summoner's Aeon has a different name, i.e. Yuna's is Bahamut but Isaaru's is the same Aeon with a different name.