Responses
I feel like the population should of noticed by now if it was every so many years because they would tell stories of how the saintess dying to protect them. Maybe not the entire commoner people, but at least some of them might have caught on since anyone who did any sort of good deed or a great fighter had bards write and sing about those types of tales. But then again we have people in our world who have no idea where food comes from other than a grocery store or that octopi are actually a real species of animal.
How often have they sacrificed otherworldly saintesses? One every year?
I mean the sacrifice loads the white crystal, which powers the barrier and summons another saintess. The saintess is taught how to use her powers for one year and is then sacrificed.
Or does the crystal store that power for several years before the next summoning has to take place?
If we take into account that nobody except the upper echelon knows about the sacrifices the latter seems more plausible because the people would notice if every white saintess has only a lifespan of one year after ascending to her post, if that would happen frequently, but if it only happens once or twice in a lifetime they may not notice.