Somnus Lucis Caelum

Somnus Lucis Caelum, commonly known as the Founder King (as the historical person) and as the Mystic (as the Lucii—a spirit residing in the Ring of the Lucii) is the first king of Lucis in Final Fantasy XV Universe who lived 2,000 years ago. He appears as a Lucii in Final Fantasy XV (extended appearance in the Windows/Royal Edition) and Kingsglaive: Final Fantasy XV, and as a human in Final Fantasy XV: Episode Ardyn and Final Fantasy XV: Episode Ardyn – Prologue. The Mystic is the most prominent Lucii, acting as the spokesperson for the collective of kings in the movie.