Ill admit at some points i was like "alright just give me my ****ing aeon!" and it was kind of a bummer to unlock the Baaj temple only to find you need all the items from each trials to get Anima... im still trying (failing) to defeat Dark Shiva so i can get the item at Macalania Temple...

Although after a few runs of the game the trials themselves lose their difficulty but i think there should be something else at the end of it, like having to fight the aeon your trying to get to earn its trust or something.