Rhea, the archbishop of the Church of Seiros and head of Garreg Mach Monastery. She possesses a major Crest of Seiros and is responsible for inviting Byleth (the player) to work as a professor at the Officer's Academy. She is kind and radiates a certain warmth, especially towards Byleth, but she ruthlessly crushes opposition to the Church's interests.

Character synopsis aside, Rhea is one of the most divisive characters in Three Houses and it's not hard to see why, especially with the harsh ideological contrast the game sets up between her and Edelgard. Her motivations are deeply rooted in personal grief, and at times she invites sympathy while at others she appears less than human. I won't contest her moral failings, but I will say that I find her characterisation to be a shockingly accurate portrayal of an autocratic leader who has been in power for so long that personal whims override the responsibility of doing what is best for the people. The books in the Abyss library on the restriction of technological and medical advancements make an especially potent comment on theocracy and religion as it relates to repression, in a way that draws parallels with the real history of many scientists, especially astronomers, being labelled heretics or conjurers by the Church in the interest of protecting a religious worldview.

That's my piece said for now, please don't forget to check out the alts I've made for this skin:
(Rhea as she appears after the timeskip in Verdant Wind, Silver Snow and Azure Moon)