I mean, this is just the plot of every FF game going back to like.... FF4 with Rydia. The PC summoners in XI absorbed a power of the summons. So did Yuna in her temple trials. So did Noctis in the tests the gods gave him.
Pretty sure the summoner class in almost every game where it exists has to undergo some kind of trial to obtain the power over that summons, whether it's absorbing part of the power or just getting a handy materia drop.