I think it would be interesting to visit harmonia and the circle rune, i have a wild theory that the opposite of the circle rune is in fact the eight fold rune.
heres why: circle symbolizes harmony and order and an eight symbolizes infinity or chaos. I believe that these runes from the limited info we received about them are actually the opposites of each other like sun and night. A war can finally sprout in the midst of Harmonia as a result of the eightfold rune, and the circle rune could contest it to restore order and harmony to their land, maybe crazy, maybe a good idea, i don't really know.