After completing his education, Hubert becomes Marquis Vestra following his father's assassination and Minister of the Imperial Household sometime after.

If Edelgard is sided with after it is revealed that she was the Flame Emperor, in Imperial Year 1185, Hubert assists Edelgard in forming the Black Eagle Strike Force at Garreg Mach. He serves as an adviser to both Edelgard and Byleth, using his tactical prowess to help guide them through battles.

Starting their campaign against the Church, Hubert reveals to Byleth and the others that Edelgard has begun purging corrupt nobles in their absence, which also included his father. During the first attack on Garreg Mach, he warns Byleth to dodge an incoming attack from The Immaculate One, but Byleth is hit and is sent into a five-year coma. Hubert, along with the rest of his classmates, continue the war against the Church for the next five years, not losing anyone in the process. He and the rest of his classmates are happy to see Byleth again during their reunion.

In order to stabilize the three-way war, Hubert suggests they deal with the Alliance first, and the fastest way to reach the capital of Derdriu is to use the Great Bridge of Myrddin. As expected, Alliance forces are guarding the bridge, led by Judith. Hubert advises they deal with her quickly before enemy reinforcements arrive.

Following the capture of the bridge, Hubert is pleased to see his classmates' morale has boosted due to Byleth's reemergence, though Edelgard reminds him that his too has also gone up due to their professor returning. As Edelgard and Byleth are discussing about Claude, Hubert comes in and informs the two that he is planning something, as the citizens of Derdriu cannot come and go as they please, warning Byleth not to underestimate him. He also stresses the importance of capturing Derdriu, as several Alliance leaders loathe Claude, and if they defeat him, they would be "tripping over themselves" joining the Empire.

Claude is defeated during the siege; regardless of the outcome, the Alliance surrenders to the Empire. Hubert arranges the transition by having Count Bergliez handle the Alliance's affairs, and the Black Eagles return to the monastery following their victory.

As they return to the monastery, Hubert informs Edelgard that her uncle is collecting relics from the Old Alliance, though she allows him to do as he pleases. Hubert also informs Edelgard that not all of the Kingdom stands by the Church, and defeating the Kingdom's most notable Houses would cause the others to fall in line; primarily House Fraldarius, Galatea, Gautier and Charon, and that they have allies inside they could help them.

In Hubert's Paralogue, Lord Volkhard informs Hubert that his subordinates were experimenting and caused some Demonic Beasts to break free, and requests for him to save his men and put the beasts out of their misery. Hubert and his classmates arrive and save as many of the mages as possible. Though they are ungrateful, they give the Strike Force the Arrow of Indra as a reward. Volkhard thanks Hubert for saving his men, though Hubert believed Those Who Slither in the Dark wanted to show them that they were helpless, but their psychological attempt backfired.

The Church later attempts to recapture Garreg Mach, and Hubert accompanies the rest of his classmates to protect the monastery. He notes that the layout of the Knights is unusual, warning the Professor to watch out for any traps and reinforcements. Following their victory over the Church, Hubert witnesses Randolph's death and gives Edelgard a status report of the battle, commenting on Alois' (if he wasn't recruited) and Seteth's deaths (if Byleth did not land the finishing blow) in the process.

Edelgard moved her forces to capture Arianrhod, where Hubert witnesses Cornelia send her Titanus out to battle; he is impressed by her magical weapons, but regardless, Arianrhod is captured and Cornelia is slain. After Volkhard cryptically states that he hoped the Empire would not be another Arianrhod, Hubert comes in and informs Edelgard that the city was annihilated by javelins of light, causing the death of most of House Rowe's leaders and numerous Imperial forces. He wonders if they had acted too rashly in killing Cornelia, but Edelgard assures him otherwise as they forced Those Who Slither in the Dark to reveal their secret weapon. Edelgard orders him to keep the full report under wraps, which he immediately complies with by telling the others that the Church was responsible for destroying Arianrhod.

Prior to the battle at the Tailtean Plains, Dimitri moves his forces to intercept the Empire, knowing the Knights of Seiros would arrive. Hubert, knowing Dimitri would never battle like this, had anticipated this move and ordered the army to watch out for attacks from the rear and sides. Hubert also witnessed a Kingdom soldier transform into a Demonic Beast, initially believing it to be Thales' work, but quickly realized it was much simpler. He advises Byleth to quickly take out the enemy soldiers before they can transform.

As the Empire arrives in Fhirdiad, Edelgard orders the Church to surrender, but is given no response. Hubert believes they would not surrender and asks her to begin the attack. Upon hearing the roars of the Immaculate One, Edelgard begins the attack on the city, which was lit on fire by the remaining Knights of Seiros. Hubert warns Byleth and the others to avoid the fires and that to minimize losses they would have to be flexible on their approach.

Rhea is killed in the ensuing battle, finally bringing peace to Fódlan, where Hubert would serve Edelgard as the Minister of the Imperial Household. He would help gather intelligence and assist Edelgard in her silent war against Those Who Slither in the Dark. If he was defeated on Classic Mode in the Academy Phase, he will succumb to his wounds not long after the wars end.

Hubert is among the forces joining Edelgard during the three-way battle at Gronder Field. Though he proves problematic for the Kingdom Army, he is ultimately overwhelmed and forced to retreat.

Hubert mainly takes a passive role, supporting Edelgard as her advisor. He does make a few appearances as the boss of some paralogues such as Petra's and Dimitri's, but is ultimately forced to retreat for both.

After Dimitri and the Kingdom forces capture Fort Merceus, Hubert receives a message from the Kingdom, requesting for Edelgard to parley with Dimitri. Surprisingly, Edelgard accepts on a whim and meets with Dimitri and Byleth with Hubert in tow. Ultimately, the two are unable to reconcile their differences and war between the two will come to a head in the Empire.

Hubert makes a final stand in Enbarr, leading the Empire's forces to defend the city. Despite a tremendous and grueling defense, Hubert is killed and with his dying breaths, hopes that Edelgard will win. His fall leads to the capture of Enbarr, allowing Dimitri and his forces to finally face Edelgard within the Empire's castle.

Hubert is among the forces joining Edelgard during the three-way battle at Gronder Field. Though he proves problematic for the Alliance Army, he is ultimately overwhelmed and forced to retreat.

Hubert mainly takes a passive role, supporting Edelgard as her advisor. He does make an appearance as the boss for Petra and Bernadetta's paralogues, but is ultimately forced to retreat.

Hubert makes a final stand in Enbarr, leading the Empire's forces and the Death Knight to defend the city. Despite a tremendous and grueling defense, Hubert is killed and with his dying breaths, hopes that Edelgard will win. His fall leads to the capture of Enbarr, allowing the Alliance Army to finally face Edelgard within the Empire's castle.

Upon Edelgard's death in Enbarr, a surviving Imperial general delivers a posthumous contingency letter addressed to Byleth, from Hubert. Through the letter, Hubert informs Byleth of the nature of Those Who Slither in the Dark and says that it is the duty of the victor to end their ambitions. He also reveals the location of Rhea's hidden cell, allowing for her recovery and return to the monastery.

Hubert mainly takes a passive role, supporting Edelgard as her advisor. He does make an appearance as the boss for Petra and Bernadetta's paralogues, but is ultimately forced to retreat.

Hubert makes a final stand in Enbarr, leading the Empire's forces and the Death Knight to defend the city. Despite a tremendous and grueling defense, Hubert is killed and with his dying breaths, hopes that Edelgard will win. His fall leads to the capture of Enbarr, allowing the Resistance Army to finally face Edelgard within the Empire's castle.

Upon Edelgard's death in Enbarr, a surviving Imperial general delivers a posthumous contingency letter addressed to Byleth, from Hubert. Through the letter, Hubert informs Byleth of the nature of Those Who Slither in the Dark and says that it is the duty of the victor to end their ambitions. He also reveals the location of Rhea's hidden cell, allowing for her recovery and return to the monastery.

Hubert (if defeated before the time-skip on Classic Mode)

Died of his wounds after the war.

Hubert - Emperor's Confidant

Hubert devoted his life fully to the service of Edelgard. Operating in the light and the shadows alike, he disposed of countless burdens facing his emperor, using any means necessary. Though his ghastly appearance and imposing demeanor were ever feared, he paid his reputation little heed, focusing instead on his loyalty to the emperor.

Hubert and Byleth

After a fierce battle, Byleth and Edelgard finally brought the tyranny of a godlike being to an end. Though wounded in the conflict and stripped of divine power, Byleth continued to fight alongside the emperor to bring true peace. Hubert joined them in this fight, fulfilling his promise to confront those who slither in the dark head-on. In that darkness, Byleth and Hubert formed an unbreakable bond. It is said that, as a married couple, they were totally inseparable.

Hubert and Edelgard

As the new Adrestian emperor, Edelgard gave all she had to breathe new life into the government of Fódlan. With tireless work, great sacrifice, and her devoted servant Hubert by her side, she instituted new class reforms and helped to ensure the people's independence. Hubert was always close at hand, ready to dispose of unsavory burdens by any means necessary. In their later years, they passed the fruits of her labor on to Edelgard's successor and vanished from the public eye. Though it is said they spent the rest of their lives together, it is unlikely they ever gave voice to the true depth of their affections.

Hubert and Ferdinand

Hubert and Ferdinand became the left and right hands of Emperor Edelgard, competing constantly with each other to see who could be the more helpful. They were opposites - The Minister of the Imperial Household, melancholy and merciless, and the prime minister, bright and compassionate. Still, they brought out the best in each other. As the empire became orderly and prosperous, the two came to be known as the nation's "Two Jewels," and were remembered fondly for generations to come. Some say their fame made even Emperor Edelgard jealous.

Hubert and Bernadetta

The marriage between Hubert, Minister of the Imperial Household, and Bernadetta, leader of House Varley, was so surprising to the public that it was much talked about even outside of political circles in the capital. Bernadetta took the opportunity to survey the far reaches of the new Adrestian Empire, and in her absence, Hubert took well to the management of Varley territory. They proved to be an astonishingly good match, working together to protect Fódlan from the shadows. It is said that they showed their affection for one another by wearing matching embroidered flowers.

Hubert and Dorothea

After the war, the Mittlefrank Opera Company made a resurgence, in no small part thanks to the patronage of Emperor Edelgard's confidant, Hubert. Dorothea made a comeback as a songstress in the troupe, which traveled all over Fódlan, putting a large share of its profits towards relief efforts. The opera company was warmly welcomed by the war-weary people as a source of solace, and became even more famous than before. It was not discovered until many years later that the troupe's tour had been a covert operation, coordinated by Hubert and Dorothea, to gather intelligence for the Empire.

Hubert and Petra

Shortly after the war, Brigid renegotiated its diplomatic arrangement with the Adrestian Empire, ending its service as a vassal and becoming a full ally. As part of that agreement, Petra, queen of Brigid, was wed to Hubert, Marquis Vestra. Some say that the marriage was purely political, ordered by Emperor Edelgard, while others insist that it was of their own accord. Although they led busy lives, and sometimes lived separately. Still, their shared home in the western Fódlan village of Nuvelle was filled with their many children, suggesting a loving union.