Nyx Ulric

""No, my life is nothing. Giving the future to those who want to see it…is everything.""

- Nyx to the spirits of the Lucian kings

Nyx Ulric is the main protagonist of Kingsglaive: Final Fantasy XV and a member of the eponymous Kingsglaive. Hailing from Galahd, he is tasked with protecting Princess Lunafreya of Tenebrae when Niflheim invades Lucis.

He is voiced by Aaron Paul in the English version and Gō Ayano in the Japanese version.

Appearance and Personality
Nyx is a young man with brown hair and blue eyes. He wears the black uniform typical of his fellow Glaives, but his is customized with a silver horn on its hood, purple ribbons on its back, and pelts of blue-gray fur on its left sleeve. The horn may be in allusion to King Regis, who wears a hornlike crown on the same side as Nyx has his horn.

Nyx has small and subtle tattoos. He has a "crow's foot" on his right cheek, and a line and a dot under his left eye. He has markings on his ears, a line down his neck, one around his right leg and a line down his middle finger of his left hand, and another down his forefinger on his right hand.

Nyx is a heroic individual who feels indebted to King Regis. He is confident in his abilities, but is haunted by the memory of his sister's death, which can cause him to have flashbacks during battles whenever his friends are in danger of not being able to save her. This is why he does all in his power to save his comrades, who call him by the moniker "hero" from his exploits. When his comrades betray him, Nyx remains loyal to the Lucian royal family, as well as his best friend Libertus and Lady Lunafreya; when Insomnia falls, he hangs onto hope and resolves to fight for the future thanks to Lunafreya's encouragement about Nyx's sister wanting him to see a brighter future.

Nyx is selfless, as he refuses to choose between Libertus or Lunafreya when requesting the power from the Ring of the Lucii. Nyx elects to instead sacrifice his own life to the past Lucian kings' spirits, who grant the ring's power to those they deem worthy. Nyx bargains with them knowing that the price for using the ring's powers for those not of the Lucian royal blood is a life. Unlike his former mentor and superior, Titus Drautos, who was also General Glauca, Nyx can move on from his past to fight to help give the world a future, something that would not happen if Niflheim claimed the Ring of the Lucii instead of Prince Noctis. As a result, he was no longer fighting to protect Insomnia and did not care what happened to the city as long as he kept the Ring of Lucii away from the Empire's hands.

Although he is selfless, it can be interpreted as arrogance, which leads to the old kings initially judging him as unworthy. Even when he proves his worth, Nyx gloats, saying the kings would lose their "precious ring" if they burn him.

Abilities
Nyx is a skilled wielder of the Lucian royal family's powers. He favors his ability to warp, and when he is deemed worthy of the Ring of the Lucii, he becomes even more powerful and gains the ability to control the Old Wall. He is once shown wielding fire in his hand while watching television in his apartment, almost identical to an earlier scene of King Regis wielding fire while on his throne, displaying Nyx's talent at wielding some of the king's powers.

Kingsglaive: Final Fantasy XV
Nyx grew up alongside Libertus Ostium in Galahd. His sister was killed, and he was saved by King Regis of Lucis. Seeking to repay his debt to the monarch, Nyx joined the Kingsglaive, an elite unit of soldiers whose members are chosen for their aptitude for magic.

Alongside his fellow Glaives, Nyx defends the borders of Lucis from Niflheim and Tenebrae's forces. He disobeys Captain Drautos's order to retreat, and instead chooses to save Libertus, his childhood friend, from Cerberus, a powerful three headed beast. As punishment Nyx is placed on guard duty upon his return to Insomnia, the crown city of Lucis.

Three days before a peace treaty is to be signed between King Regis of Lucis and Emperor Iedolas Aldercapt of Niflheim, Nyx is relocated to the Citadel by Drautos. As mentioned in Final Fantasy XV Prologue Parting Ways, Drautos has Nyx drop Noctis off to his place as thanks for using his car. The men discuss the death of Crowe Altius, and the next day, Nyx gets into a heated argument with Libertus after seeing Crowe's corpse. That evening, Nyx attends a party celebrating the treaty signing and meets Princess Lunafreya Nox Fleuret.

On the day the peace treaty is to be signed, Nyx discovers Lunafreya has been kidnapped and Drautos has mysteriously disappeared. He demands the Kingsglaive's deployment from King Regis, and leads his comrades on a mission aboard a Niflheim airship to rescue the princess. Nyx is betrayed by a majority of his fellow Glaives who disagree with the peace treaty terms and deem the king has abandoned them. Nyx frees Lunafreya and uses the airship to fly back to the Citadel with her. They witness the Wall fall as Niflheim begins its invasion, deploying daemons and magitek infantry to annihilate the city. Nyx and Lunafreya help a wounded King Regis escape Imperial General Glauca, who seeks the Ring of the Lucii, a ring that gives special powers to the past kings' chosen.

At the end of a secret passageway, Nyx questions King Regis's decision to sacrifice Insomnia for Prince Noctis's continued safety. He agrees to protect Lunafreya, who is given the Ring of the Lucii, and flees with her after Regis is impaled by Glauca's blade.

As he and Lunafreya drive away from the Citadel, Nyx is contacted by Drautos and ordered to rendezvous with him in Section D of Insomnia. In the city plaza, he is attacked by a fellow Glaive Luche Lazarus and discovers through Libertus's intervention that Drautos is Glauca. To protect his friends, Nyx puts on the Ring of the Lucii and is granted its power in exchange for his life. After ordering Libertus to get Lunafreya somewhere safe, he gives her the ring to deliver it to Noctis. Nyx engages Glauca while wielding the power of the old kings. In the clash's aftermath, Nyx dies peacefully as he wishes Noctis a healthy rule.

Final Fantasy XV
Ten years after the world is plunged into darkness with the Starscourge, an illusory version of Nyx's corpse hangs in chains from the ceiling of the Citadel's throne room. Ardyn Izunia uses it to discourage Noctis. The corpse has white crystalline scarring, showing the damage Nyx sustained by using the Ring of the Lucii.