A young dragoon tasked with guarding the sealed dragon in Dragon's Village. He has mastered the art of dragon sealing, a skill which only a chosen few can inherit. Knowing that his dragoon ancestor made the ultimate sacrifice in order to seal the dragon, Duke is ready to follow in those footsteps should the time ever come.
Duke is a supporting character in Final Fantasy Brave Exvius. He comes from a long line of dragoons who watch over Dragon's Village, in the continent of Georl, and keep an eye over a sealed evil dragon. He is also a leader of the Resistance against the Aldore empire. He is assisted in his duties by his childhood friends Olif, Mystea and Charie.
Having developed quite a stern personality due to his dragoon training, Duke is the quiet type, but he cares deeply about his friends. He is reliable and earnest—his comrades place a great deal of trust in him—, but also has a self-sacrificial and stubborn side: Duke feels a deep admiration for his ancestor, who sacrificed his life in order to seal the dragon, and is ready to follow in those footsteps should the time ever come, even though his friends' supportive skills are meant to prevent that from happening.
A descendant of the legendary dragoon Ryunan, Duke was born to the ancient clan known as the dragon sealers that resides in Dragon's Village. As such, Duke was entrusted with the mission to protect the seal of a dragon that once terrorized Paladia, and trained from childhood to become a dragoon. In his duty, he had the company of peers who likewise work to keep the dragon sealed: Olif, Mystea and Charie. Olif, the oldest, is the unofficial guardian of the group, while Mystea, almost like an older sister to Duke, is one of the few people who knows Duke's secret, and thus watches over him affectionately. Charie, for her part, is like a younger sister to Duke. When they were litte, Charie once showed Duke a weird dance to make him loosen up, which Mystea found amusing.
Duke trained himself day in and day out until he mastered the art of dragon sealing, a skill which only a chosen few can inherit. When Duke gained prominence among his clan as a Dragoon, he retired his beloved Drakeshorn Spear and took up the legendary Virtue Drake, a heavy spear passed on through his clan's generations that had long been in storage.
Eventually everyone in the village joined the Resistance, which opposes the tyrannical rule of the Aldore Emperor. Duke himself serves as a leader of the Resistance, but finds it difficult to fulfill the duties of his post whilst attempting to accomplish his dragoon duties.
In "Where Destinies Intersect" Duke is hiding atop a tree when Lexa and Merald, members of Morze's Soirée, hide in the bushes below while trying to avoid Galas of The Orders and his soldiers. Duke jumps to Lexa and Merald's side and offers to help them get away. Far away from the soldiers, the girls thank Duke, but he simply asks whether they saw Charie, who is missing. He reflects that searching blindly won't get him anywhere and decides to wait for Charie at the village. He also helps Lexa and Merald save a grandmother and her grandson from soldiers. When the stewardesses ask him about Dragon's Village, Duke leads them to his hometown. Eventually, Charie turns up at the village with Elbis and Nichol.
Duke briefly meets Lasswell's party when they are led to the village by a prisoner they saved from execution at the hands of Galas. Duke is guarding the entrance and orders them not to move, but the man they saved swears on his honor that they aren't enemy spies. Duke lets them enter the village, and apologizes to the villager for not being able to go rescue him.
In "Fate of the Dragoon", Charie confides in Duke that she senses the seal may be weakening. When Duke checks, the dragon's seal is functioning properly, and wonders if it is due to spending time away to help with Resistance activities. As they move farther in, a dragon attacks them and the two end up separated. Trusting her resilience, Duke returns to the village to meet her, Olif and Mystea, all the while suspecting that the seal has been broken. At the village, he meets with Olif and Mystea; they ask about Charie's whereabouts and Duke explains that they lost sight of each other. The two then accompany Duke up the mountain where they are to re-seal the dragon.
Anxious to do his duty, Duke rushes ahead of Mystea and Olif, and waits for them next to a waterfall when he meets a young dragoon, who demands to know why Duke is by himself. When he assures that his friends are just a litte behind, the dragoon boy tells Duke to go further only if his friends are with him; otherwise he will be in trouble. He then leaves. Duke, demanding to know his identity, follows him and goes ahead once again. When Mystea and Olif finally catch up with Duke, she rebukes him for his lack of self-preservation. Olif later voices that they understand Duke's determination, but that they also want to protect him from such a dire fate. They finally meet Charie and, after fending off a monster's attack, Duke apologizes and asks his friends to lend him their strength.
The young dragoon reappears, whom Charie calls by his name: Ryunan. Duke reacts to the name, as it is that of his legendary ancestor. Ryunan thus admits to being merely a strong "memory", guessing that Duke is the offspring of his younger brother. Duke is honored to be in his presence, but Ryunan reveals that the legends embellished his death and asks Duke not to make the mistake that he did. Before parting, he asks that they retrieve his spear Northern Lights and return it to the village. Ultimately Duke is able to seal the dragon and find the spear, which they later return to their ancestors' graves.
Sometime later, the quartet undertake a cleanup operation at the Vesta Ruins, where a den of monsters has gone berserk, likely an effect of the dragon's resurrection. As the dragon's influence should have waned due to the seal, they suspect that someone unknown is interfering with its power and decide to investigate some more. After defeating the fairy responsible, they return to the village.
Duke appears as a 5-7★ summonable unit. He is a Dragoon closely associated to the Ice element, and is geared towards jumping. When using his 'timed jumps', he can drop from the sky at the player's pressing of a button, and cap chains for increased damage (and is thus a reliable 'finisher', especially against Dragon-type monsters). His weapon of choice is the spear, but he can also equip swords and greatswords. As for armor selection, he can equip light shields, hats, helms, light armor, heavy armor and accessories.