Hennix, a Quarren male who possessed Force-sensitivity, became a Jedi Padawan during the New Republic Era. He joined the Jedi Order under the guidance of Jedi Master Luke Skywalker. After the destruction of Luke Skywalker's Jedi Temple, Hennix, along with Voe and Tai, challenged Ben Solo's version of events, doubting his claim that Master Skywalker had attacked him. When Solo attempted to depart, Hennix and the other Jedi tried to stop him, but Solo escaped, leaving Hennix wounded. The three Jedi pursued Solo to the planet Elphrona, where they engaged in a lightsaber duel. Hennix met his end during this confrontation, leading Voe and Tai to believe that Solo was beyond redemption.
Around 16 ABY, Hennix, gifted with Force-sensitivity, commenced his training as a padawan at Luke Skywalker's Jedi temple, under the instruction of Jedi Master Luke Skywalker. He trained alongside fellow initiates Ben Solo, Voe, and Tai. In his youth, Hennix and his peers learned the art of telekinesis to levitate rocks. He perceived the Force as an intricate enigma, showing a particular interest in the holocron belonging to Avar Kriss, a Jedi from the High Republic Era.
Soon after Solo destroyed Skywalker's temple in a destructive storm, Hennix, accompanied by Voe and Tai, arrived in their starship, the Verity. While searching for any survivors, the three Jedi encountered Solo, who claimed that Master Skywalker had attempted to murder him in his sleep. Solo suggested they should leave, but Hennix and his companions insisted on questioning him.
Despite Tai's efforts to de-escalate the situation, Hennix and Voe ignited their lightsabers. Voe launched an attack on Solo, but he used the Force to suspend her in mid-air before throwing her into Hennix. The trio of Jedi attempted to subdue Ben, but he retaliated by using the Force to hurl burning wood and debris at them. A fragment of debris struck Hennix in the abdomen, causing a significant wound.
With Hennix injured, Solo made his escape aboard his starship, the Grimtaash. The Jedi returned to the Verity. While Tai tended to Hennix's injuries, Voe pursued Ben's ship. However, Solo successfully evaded capture by damaging one of the Verity's engines. As Voe and Tai debated their next course of action, Hennix proposed that they track Ben Solo's ship by using a transponder located inside his droid, Geegee, who was aboard the Grimtaash.
Hennix, Tai, and Voe successfully tracked Ben Solo to the Jedi outpost situated on the planet Elphrona. They engaged Solo in a fierce lightsaber duel. While Tai attempted to pacify Solo by delving into his mind, Voe pursued Solo, utilizing a Force jump to reach a large rock. Hennix, unable to match Voe's agility, cautioned her against venturing too far, as he was unable to keep pace.
Voe and Hennix attempted to corner Solo, who responded by using a Force push to send Voe off a cliff. Overcome with remorse, Solo attempted to save her, but he was attacked by an enraged Hennix, who believed that Solo had caused her death. Managing to reach the cliff's edge, Hennix hurled his lightsaber at Solo, but it was deflected. Caught off guard, Hennix was struck by the returning blade and killed. In an attempt to deter the Jedi from pursuing him further, Solo buried Tai and Voe under two Jedi statues.
While Solo departed to find the Knights of Ren, Tai and Voe used the Force to free themselves from the rubble. After tending to their dying comrade, Voe and Tai vowed to avenge Hennix's death and to stop Solo, whom they now considered to be lost.
Solo later recounted Hennix's death to the Knights of Ren and their leader, Ren. However, Ren deemed Hennix's death to be dishonorable because Solo had not intended to kill the Jedi. Nevertheless, he permitted Solo to join his Knights, believing that Solo could prove his worth through a "good death."
Hennix, a Quarren male with brown skin, shared a close bond with Ben Solo, Voe, and Tai. He was known for his analytical approach to the Force, viewing it as a complex puzzle that could be understood through dedicated study. Solo observed that while Hennix understood he could not solve the mysteries of the Force, he would have been content spending his life trying. Hennix was considered intelligent and humorous by his fellow apprentices at Skywalker's Jedi temple, including Solo.
After Skywalker attacked Solo, Hennix and Voe believed that Solo had destroyed the temple and killed Skywalker while Tai advised caution. Hennix came up with the idea of tracking Solo through hyperspace by following the transponder on his droid Geegee.
Like Voe, Hennix believed that Solo needed to be stopped. When Solo Force pushed Voe down a cliff, an enraged Hennix tried to avenge her.
Hennix possessed Force-sensitivity and wielded a blue lightsaber. Despite his Force abilities and lightsaber skills, he was still outmatched by Ben Solo. Hennix also had a keen interest in holocrons. While Hennix was able to open a holocron after listening and concentrating, he seemed to not do very well in combat scenarios where he was under pressure. Unlike his fellow student Voe, Hennix couldn't Force jump and while he threw his saber at Ben Solo, he was unable to repel it when Solo threw his saber back at him, which ultimately killed him. While he could not understand Huttese, Hennix was fluent in Galactic Basic Standard.
Hennix wore tan Jedi apparel. He possessed a blue-bladed lightsaber.
Hennix made his debut appearance in the Marvel Comics comic mini-series Star Wars: The Rise of Kylo Ren, which began with the release of The Rise of Kylo Ren 1 on December 18, 2019. He was brought to life by comic writer Charles Soule and artist Will Sliney.