"Don't go for Ifrit," Kadaj said, looking at Ignis. "There's only one Aeon. If you and Tayuya were in the same fight and she summoned him, you wouldn't be able to. Ifrit's pretty popular, so you've got to be as good as Tayuya to be sure he'll actually come to you every time. Otherwise, if someone else is calling him, and they're stronger than you, or have a better bond with him than you, you're out of luck."

It was part of why Kadaj had gone for Bahamut. That, and showboating. Bahamut was much less newbie friendly, and his cloister of trials were a pain in the ass, so there were a lot less people in the world able to call on him.