Somnus Lucis Caelum

Somnus Lucis Caelum, more 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.

Appearance
As a human, Somnus resembled Noctis with his black hair and facial shape. He dressed in a long blue robe with buttons down the front, black sandals, a black cape, a guard on his left forearm and shoulder and a blue silk shawl around his hips attached to a strap that crossed his chest. His in Episode Ardyn Prologue resembles the Kingly Raiment attire Noctis and his father wear in Final Fantasy XV.

As a Lucii the Mystic has holes on his winged helmet and the back of his suit of armor has something similar to a bony tail. The winged/horned helmet and the "tail" could allude to Bahamut, the Astral god who chose the Lucis Caelum line for a greater purpose in the world. Every successive Lucii has had a similar appearance, yet unique to their personality; the dark suits of armor they wear resemble Bahamut who presents himself similarly.

In the artwork of the Cosmogony, the Founder King is portrayed as a black-haired man wearing a golden crown and a gray cloak. In Episode Ardyn Prologue, it is Somnus's exiled brother Ardyn who wears the cloak and has long hair.

Somnus's weapon is an elaborate longsword that would become known as the Blade of the Mystic.

Personality
As a Lucii, the Mystic appears steadfast, determined and loyal to the Crystal's cause, but strict with those who seek the power of the Ring of the Lucii without being of the royal bloodline.

When Nyx Ulric puts on the ring to ask for the power to save Insomnia, the Mystic considers the opinion of the recently arrived King Regis. Despite being angered by what he considers Nyx's arrogance and short-sightedness, the latter's selfless determination to protect the future impresses the Mystic enough to agree to lend him the power of the kings. After being freed from Ardyn's brainwashing, the Mystic praises Noctis and his retinue for their performance and urges Noctis to fulfill his calling, asking him to free his fallen brother from the thrall of darkness.

Despite all Ardyn had done, the Mystic acknowledges their familiar relation. In the Episode Ardyn teaser trailer, Somnus refers to Ardyn as 兄上, a formal and old fashioned term for "older brother" used to show respect. However, in the Episode Ardyn Prologue, Somnus does not hesitate to fight Ardyn whom he considers a traitor, willing to steal the throne. He is described by the directors of Episode Ardyn as a realist and a severe king who doesn't despise Ardyn even if he condemns him; the two simply had a different idea on how to save the world. Although his actions of burning alive all who got infected show he is willing to forgo all morals, Somnus strove for the greater good of Eos.

The Cosmogony books describe the Founder King as a hero archetype who freed Eos from darkness, having been chosen by the Ring of the Lucii for his worthiness, never mentioning Ardyn. Ardyn meanwhile describes his younger brother as the person who stole his glory and demonized him out of jealousy. Episode Ardyn Prologue shows Somnus as a ruthless person who lets not even familial bonds stand in the way of his goals.

Abilities
Somnus had many of the same powers his brother and descendants display, wielding "weapons of light," conjuring them from thin air at will. He can warp and use magic. The kings' sigils bestow their wielders with each king's specific abilities, and the Founder King's Sigil empowering Noctis's Armiger to a stronger version. In Final Fantasy XV: Comrades, the Mystic's Sigil: Graviton allows the bearer to create a powerful gravitational force that draws enemies close, while limiting their abilities.

According to Ignis Scientia, legend has it "the King once stood alongside the Six in the battle to banish the darkness", referring to Somnus halting the spread of Starscourge. The story has become folklore and is the basis of the prophecy of the True King, but the details of Somnus's quest to save the world are unknown. Due to his mesmerizing battle performance he earned the title "The Mystic". As a Lucii, he is the most powerful out of the three kings of yore Ardyn ushers to fight Noctis and his retinue. The Mystic ejects energy from his sword to hit ranged targets, warp-strikes, and uses powerful elemental magic. When tainted by the Starscourge he can project a tornado of miasma that sucks all in close proximity in, and as he grows weaker, he becomes more ferocious. As an Old Wall statue in Kingsglaive: Final Fantasy XV, the Mystic warps and destroys the remaining Diamond Weapons with his fists after his sword is destroyed. In Episode Ardyn, the Mystic, when fought by his brother as a boss, can empower his sword with light.

Story
Somnus is the younger brother of Ardyn Lucis Caelum. When they were young the two used to play chess, and Somnus went on hunting trips with Gilgamesh in his childhood. Although Final Fantasy XV posits that Ardyn was to become the first king of Lucis before falling from the Crystal's favor, Episode Ardyn — Prologue depicts the choice between the two brothers as having been up in the air at the whims of the gods. Both Ardyn and Somnus strove to protect their realm from the daemon outbreak, Ardyn by healing those infected by the Starscourge one by one, whereas Somnus rounded them up with his army to exterminate them. Ardyn abhorred Somnus's methods, but absorbing the malady into his own body was slowly twisting him into a daemon as well.

Bahamut delivered the gods' decision to the Oracle, Aera Mils Fleuret. Somnus sought her out, but she was reluctant to tell him. Relenting, she divulged what she had learned and Ardyn soon received word he was to be crowned. When Ardyn arrived at the castle where the Crystal was kept, Somnus suddenly declared himself as the king chosen by gods, shocking Aera when he claimed Ardyn's announcement had been a ruse to lure him out of hiding. Somnus fought Ardyn and impaled him on his spear. Aera (Ardyn's fiancée) rushed between the brothers and took a blow meant for Ardyn, dying in his arms. Ardyn transformed into a daemon, and after lamenting his brother had truly became the monster he had made him out to be, Somnus attacked him alongside his sworn shield Gilgamesh.

Ardyn sought confirmation on the gods' choice from the Crystal, but was thrown back as the Stone rejected him as unworthy. Somnus executed Ardyn, but discovered his brother had become immortal. Ardyn was imprisoned in Angelgard for the next 2000 years while Somnus ascended the throne.

The Cosmogony puts forth a different tale of Somnus's ascension, never mentioning Ardyn. According to it Somnus rose to protect the first Oracle, a maiden whom Bahamut granted powers to fight the Starscourge and commune with the Astrals. Together, Somnus and the Oracle set out on a journey where she helped him forge covenants with the Astrals who would test his prowess with trials that laid waste to entire cities. With the Astrals by his side, Somnus is said to have collected a collection of glaives of light and eradicated Starscourge from Eos with them.

Somnus became known as the Founder King and was served by Gilgamesh as his sworn shield, and Shield of the King would become the title given to the Lucian monarch's main bodyguard. Somnus was granted the Crystal of Eos, the very soul of the star, and the Ring of the Lucii, a magical ring that allows the wielder to commune with the Crystal and collects his bloodline's souls. One day in the distant future the final king would become the fabled True King, chosen by the Crystal. Until that day arrives, Somnus and his descendants are sworn to protect the Stone and the Ring.

The civilization of Solheim in ruin, Somnus could establish a new kingdom in its place: Lucis. The Cosmogony books that chronicle the legends of Eos posit that before falling into eternal slumber, having been exhausted by the War of the Astrals, the Six gave mankind the Ring of the Lucii. The ring is said to have passed from person to person, but none were fit to inherit its power. It is said to have found its way into the hands of a person deemed worthy, whom the populace thus saw fit to rule, who became the first king of Lucis. However, this account may not be accurate, as the Cosmogony never mentions Somnus's brother. Final Fantasy XV Official Works posits that Somnus founded Lucis to protect the Crystal and the Ring of the Lucii, and to prepare for the "Calamity to Come". Episode Ardyn — Prologue depicts the gods choosing the king directly and delivering their decision to the Oracle via the Crystal.

Somnus was likely the first to entomb his longsword to preserve it for the future generations of his lineage, an array of holy weapons that would become known as the royal arms. After he died his spirit came to inhabit a colossal statue likeness of him, in present day known as part of the Old Wall. The statues animate at the behest of the currently reigning monarch to protect the Crown City of Insomnia where the sacred Crystal is kept. Somnus was the start of the Lucian royal line, and after death his soul entered the Ring of the Lucii. For the next 2,000 years, his spirit resides in the ring, bonded to the souls of his descendants to empower them, now remembered as the Mystic and the Founder King.

As depicted in Final Fantasy XV: Episode Ardyn, Ardyn returns to Lucis after his two millennia captivity and confronts Somnus's Lucii form in Insomnia, now consumed by hatred for his bloodline.

As depicted in Kingsglaive: Final Fantasy XV, the Mystic talks to Nyx Ulric when the Glaive puts on the Ring of the Lucii. As Nyx is not of royal lineage, he must pay the blood price for gaining the ring's power. The Mystic at first offers for Nyx the choice between his friends Lunafreya Nox Fleuret and Libertus Ostium, but Nyx is only willing to sacrifice his own life. After support from the Father, the latest Lucii to join the ring, the Mystic and the others accept Nyx's bargain and he gains the power to animate the Old Wall. The Mystic's statue comes alive and fights the Niflheim forces decimating the Crown City even if the Crystal has already been stolen, and is the last king standing at the battle's end. The statue's greatsword (a colossal version of the Blade of the Mystic) breaks in the final stretch of the battle against a Diamond Weapon, so he tosses it aside and punches the Weapon instead. Nyx digs his kukri into the Mystic's suit of armor to follow the king warping away.

In Final Fantasy XV, Noctis Lucis Caelum, the 114th heir to the throne of Lucis, comes upon the Tomb of the Mystic at the Disc of Cauthess where he inherits the Blade of the Mystic. The magical energy of the tomb is set free when the Oracle Lunafreya awakens the sea goddess Leviathan and grants Noctis a sustained form of Armiger to pass her trial. Noctis eventually recovers the Ring of the Lucii and finds the Crystal the empire had stolen away. He is pulled into an otherworldly realm where the Astral god Bahamut tells him of his role as the culmination of the kings of Lucis: Noctis is the True King whose blood price can save the world from the Starscourge.

Noctis spends ten years sleeping inside the Crystal to absorb its power before returning to the daemon-infested Insomnia to bring light back to the world. In the Royal Edition content, the Mystic is enslaved by the Starscourge and used by Ardyn to test Noctis in the Hall of History. Following his defeat, Somnus asks Noctis to free Ardyn from his state as the Accursed. During the final duel between Ardyn and Noctis, the Mystic is among the Lucii who materialize beyond the Citadel.

After killing Ardyn's physical body and sending his immortal soul into the in-between realm, Noctis sits on the throne of Lucis and summons the Lucii, who plunge their royal arms into him. Noctis and the Lucii emerge to face Ardyn's corrupted spirit in the "beyond", and the royal arms eject from the former's body. The Mystic once again takes up arms with the Blade of the Mystic as the Lucii combine their powers in the true form of Armiger to destroy the Starscourge inside his brother once and for all. The sun rises, daemons disappear from the world, and the Ring of the Lucii shatters.

Blade of the Mystic
Blade of the Mystic is the fourth royal arm obtained during the main quest, found at the Disc of Cauthess in Chapter 4. It is a longsword that boosts the wielder's Strength through a unique self-buff. Its basic combo has Noctis perform myriad slashes and stabs at medium speed and area of effect. When the player stops attacking, Noctis will hold the sword in front of him and gain +100 Strength for 10 seconds. This buff can be activated outside of combat. Blade of the Mystic's aerial attack is a single slash, and its phase-counter is an uppercut slash.

Warp-striking with the Blade of the Mystic has Noctis shoot Armiger projections before delivering the strike, a strong direct downwards slash. Each projection does the same damage as the blade would in a melee hit adjusted for warp-strike distance bonus. Due to the focused nature of the physical strike, it is good for breaking normally hard-to-reach appendages.

Noctis displays a preference for this weapon after obtaining it, as he uses it the most whenever he executes an attack that requires a royal arm. In Armiger Chain, Noctis wields it for his first attack. The blade is well balanced and a recommended addition to any arsenal.

Sigils
In Final Fantasy XV Royal Edition, the player gains access to Armiger Unleashed by interacting with the statue of the Founder King in northern Leide, in the ruins of Keycatrich. After having collected all 13 royal arms, interacting with the statue yields The Founder King's Sigil.

In Final Fantasy XV: Comrades, the Mystic's Sigil: Graviton allows the bearer to create a powerful gravitational force that draws enemies close, while limiting their abilities.

Boss
The Mystic is fought in Final Fantasy XV Royal Edition as a boss in the final dungeon.

The Mystic also appears as a boss in Final Fantasy XV: Episode Ardyn.

Creation and development
The human version of Somnus is based on Noctis, although he ended up becoming the opposite of him in many ways.

Dissidia Final Fantasy NT
The Mystic appears with the other Lucii on the Insomnia stage after the stage transitions to night.

Etymology
The Lucian royalty have three names similar to the real world of praenomen-nomen-cognomen.

Somnus appears named after "Somnus", the main theme of Final Fantasy XV. It has been the main theme of the game ever since it was announced as Final Fantasy Versus XIII, and the game still has lingering sleep motifs. Lucis's Crown City being called Insomnia could thus be in relation to its founder king. However, the god of sleep Somnus/Hypnos's brother being Thanatos ("Death") could also be an inspiration for his naming, considering Somnus in Final Fantasy XV is Ardyn's brother.

In Japanese his Lucii is known "the Yaksha King". is a class of nature-spirits, usually benevolent, who take care of the natural treasures hidden in the earth and tree roots in Hindu, Jain and Buddhist texts. The Yakshas are described in Hindu literature as the brothers of demonic beings (rakshasas).

In the English localization, his Lucii is the Mystic. Mystic is a person who attains insight into mysteries transcending ordinary human knowledge by communication with the divine.

Trivia

 * The reason the Tomb of the Mystic is at the Disc of Cauthess at the base of the Meteor is never elaborated upon. Most kings are entombed in hidden royal tombs scattered across the realm. The About the Kings of Yore document in Final Fantasy XV: Comrades posits that the tombs were erected as a memorial to the sovereign who claimed that land in the name of Lucis. Many tombs have been lost across the ages, and the Mystic's should be the oldest. All royal tombs have the same design of a depiction of a king grasping the royal arm that belongs to that particular tomb.
 * In the English localization of Final Fantasy XV: Episode Ignis, when Ardyn mentions his true name Ignis assumes he was the Founder King. Ardyn corrects him.
 * Noctis finishes the Mystic with a sword that he doesn't normally have: it has a similar yet truncated blade as the Sword of the Father and a different hilt. This is actually . that accompanied the trailer shows Regis with the Sword of the Father, however, implying the "Dawn" sword is perhaps an alternate version of it.
 * Somnus appears on a field of flowers in the Episode Ardyn teaser trailer, which appear to be asphodels. This is where he also appears alongside Lady Aera in Episode Ardyn Prologue. According to the Victorian Language of Flowers, asphodel is a type of lily meaning "my regrets follow you to the grave". In Homer's Odyssey, asphodels are everlasting flowers said to grow in the Elysian fields where spirits live.
 * Somnus's hobby is said to be "napping and hunting", drawing a parallel to Noctis.