WARNING: SPOILERS WILL BE UNMARKED
Jeanne d'Arc is a bearer of the Prima MaculaThe reason the French had so many victories over the English once she arrived is because she has the Prima Macula, the same power Hugo awakens to in the end of the game. Whether she's descended from Hugo or Amicia, she'll have indeed fought in battle. Unlike her execution, it'll be a friend of hers who takes her place at the stake.
A distant sequel set in World War 2 involves the Prima Macula involved in both sides of the warA distant descendant of the de Rune family would be hunted down by the Nazi Regime because of their bloodline, especially with the intent of giving that blood directly to Hitler himself the same way it was given to Vitalis. Even more heartbreaking would be if one of Lucas's descendants becomes a Nazi scientist who takes after the regime's biggest monster, Joseph Mengele.
The de Rune family's actions throughout the game go down in history as the famous folk tale The Pied Piper]Those who survived the de Rune's massacre of the corrupted priesthood at the end of the game would have written about 'the unrelenting Four Horsemen of the Apocalypse in the guise of women and boys'. From there, the phone game turns the original accounts written by half-mad plague survivors into a story about others wanting to take advantage of their rat-controlling power only to be crushed under a wave of corralled rats, to a story about a bard who saved the town by luring the rats into a pit, got short-changed, and then corralled their children off a cliff.
The Prima Macula is some type of parasiteSomething like toxoplasmosis.