I'm expecting a religious reform of some kind. It's pretty clear how far belief in the gods and the purpose of the temple has fallen, most nobles seem to just go through the motions with anything to do with the gods with Eglantine seeming to be the closest to actually dedicating mana to them but only through dedication whirl.
In Part 1 Myne first hears of the gods and becomes a shrine maiden at the end of it.
Part 2 she genuinely learns about the gods through the scriptures and prayer rituals as she begins to see more of the world around her, she also gains a following in the temple of the orphans and gray priests with Wilma being the most devout to Myne's saintly ways. At the end of the part she is adopted as a noble child and is slated to become High Bishop of Ehrenfest while simultaneously giving the most absurd blessing Ferd, Sil and Kars have ever seen.
Part 3 has Rozemyne showing true blessings to the commoners of the lower city who have no faith before being abruptly blessed left and right in baptism/coming of age/marriage ceremonies, this may not directly cause the commoners to become pious, but it certainly can't hurt. She also showcases her saintly mana levels to most nobles in Ehrenfest, and also happens to inadvertently make Hartmut her first apostle. Throughout the part she has full access to the sacred scriptures, takes an active role in every ritual, saves Wilfried from disgrace multiple times, and even caps off the part with a daring rescue of her beloved little sister which results in a situation where Charlotte contemplates if Rozemyne is actually a saint or more akin to a goddess.
Moving right along to Part 4 we start with Sylvester and Florencia essentially proclaiming Rozemyne as their saviour and showing her the deepest respect a noble could. An act that is later performed by Giebe Haldenzel after seeing the full extent of the true Spring Ritual brought to them by the goddesses of spring. Haldenzel also muses how he afterward truly prayed to the gods for the first time from the bottom of his heart. We also get another apostle in Clarissa and a variety of prayer related shenanigans at the RA, some of which were swept under the rug because Ferdinand was able to run interference in time.
For part 5, we know noble society doesn't understand the significance of their religion, but some of them are starting to realize its importance. The only individual who can likely hold Rozemyne back from shoving the truth in front of everyone's faces is Ferdinand, who won't be able to interfere nearly as much from a distant land (I'm assuming Part 4 ends with him officially leaving). There's also Year 3 coming up, which is the year all nobles need to memorize the names of the gods and receive blessings of some sort. Rozemyne is absolutely going to stand out here somehow, she simply isn't capable of doing anything nobles would consider standard. My guess is that whatever happens is going to lead to either more interrogations, or large scale reforms across all of Jurgenshmidt, possibly both.
