Azmuth is the creator of the Omnitrix, Ultimatrix, and Infinity Matrix, granted a majority of work on the latter was done by Azmuth's old mentor, The Master. He is responsible for The Master's initial imprisonment, hence The Master's sudden urge to kill Azmuth during his first encounter with Ben Tennyson, in which Azmuth is present.
The Master succeeds in killing Azmuth, his last real threat in his opinion (at least until he becomes more involved with Ben, Gwen, and Kevin), but the elderly Galvan's legacy lives on within Ben, as seen by the young hero's wiser decisions regarding the Infinity Matrix now that he has been left on his own to save the universe while solving its mysteries and learning to use it.
Azmuth teleports to Earth one night after Ben, Gwen, and Kevin help dozens of people escape from a burning skyscraper and the men who set fire to it and attempt to shoot the people that work in the skyscraper as they flee from the flames. He transports Ben to Galvan Mark 2 while Kevin and Gwen remain on Earth to pursue the men responsible for the fire. Once on Galvan Mark 2, Azmuth tells Ben the story of his old mentor, a being who called himself "The Master", and how this being created the inspiration for the Omnitrix, a powerful device that amplified an alien's powers to unimaginable levels, the Infinitas Anima. Azmuth then goes on to state that when The Master used his creation to amplify his powers beyond maximum level and destroy the innocent in an attempt to gain control over the universe, he imprisoned his mentor in an inter-dimensional realm inaccessible to everyone and everything that only he knew about. He tells Ben that after his mentor's imprisonment, he took the abandoned and mostly destroyed Infinitas Anima and began rebuilding it in secrecy with a belief that this device that was once intended for evil could be used, if in the hands of the right people, for good. He abandoned the project when his strange activity became suspected, however, fleeing into exile for betraying his people to Zenon. Having taken only a few fragments of the Infinitas Anima with him upon leaving Galvan, Azmuth began work on what eventually became the Omnitrix and Ultimatrix.
When Ben inquires as to why Azmuth brought him so far away from home to just to tell him his life story, Azmuth reveals the horrible possibility that The Master has escaped from imprisonment and is at large once again. Hearing this, Ben eagerly states he's ready to save the universe from this new threat, but Azmuth says, yet again, that Ben is not ready and is certainly no match for The Master. He reconsiders this statement, however, and Azmuth asks to see the Ultimatrix. Ben removes it from his wrist, giving it to Azmuth, and when it is returned to him, the elderly Galvan states again how Ben has an all-out war to determine the fate of the universe ahead of him. He then explains that he has set all aliens' Ultimate forms as Ben's default transformations, save for Alien X, whose more powerful form was locked for safety precautions. Azmuth stresses the importance of unlocking this, as Alien X is the only alien in Ben's arsenal who stands a chance of conquering The Master, let alone setting equilibrium to his powers. It is from this comment that Ben deduces The Master is a Celestialsapien of sorts. Azmuth elaborates on this, saying he is a mutated and evil creature of an unknown species estimated to be related to Celestialsapiens. The elderly Galvan then tells Ben that it was The Master who created the Forge of Creation, which Ben had previously ventured to in the fight to stop Agreggor.
Just as Ben prepares to head to the transporter nearby and return to Earth, Professor Paradox appears and complains about how The Master's ability to warp time and space has prevented a majority of his time-walking powers from working or performing to the full potential. He hands Azmuth a small, rhombus-shaped, computer chip-like object he claims to have created, and he then turns to Ben as Azmuth takes it and explains that it needs to be placed inside the hero's body. Ben agrees to allow Azmuth and Paradox to place the chip inside him, and after the process is complete, asks what the point of the procedure had been. Azmuth explains that the chip was known as the "LRS", or "Last Resort System", and that this chip would dissolve into Ben's blood and release small bacteria that would eat away at Ben's existing DNA and fuse it with those of all aliens in the Ultimatrix without harming the rest of Ben's body. This way, if anything were to happen to the Ultimatrix, Ben would still be able to access his alien forms without it. Ben then returns to Earth, Azmuth accompanying him after learning from Paradox that the LRS could still be faulty and potentially deadly, as the bacteria it contained could mutate and destroy Ben's spirit and replace his life force with those of the aliens whose DNA was contained within these potentially harmful bacteria. While Azmuth goes despite Ben's wishes to make sure nothing bad happens to him, Ben is confident that everything will be fine.
While Ben carries out the life of a hero and a high school student, Azmuth remains a secret guest at Kevin's garage. It is while Ben, Gwen, and Kevin aren't present that Azmuth takes out some once-hidden fragments of the Infinitas Anima that did not go into the Omnitrix or Ultimatrix. He begins building an upgrade for the Ultimatrix that he dubs the "Infinity Matrix", keeping this creation safe with him and away from all eyes but his own. It is during this time on Earth that Azmuth begins to bond slightly with Ben, and Azmuth even begins to bond with Kevin and Gwen, as well. Azmuth's presence is soon detected some distance away by The Master, however, who travels in Azmuth's direction with a goal of killing his old apprentice. When The Master finds Azmuth at last, an intense battle between The Master, Ben, Kevin, and Gwen over the elderly Galvan's life ensues. The Master mentioning he sensed his old powers were near (referring to the fragments of the Infinitas Anima Azmuth had hidden within his shirt), Azmuth runs for his life, intent on protecting his creation from The Master so he could not harm anymore innocent lives. Azmuth is crushed by falling rubble during this process, however, Ben, Gwen, and Kevin using all their power to dig the Galvan out. The Master fleeing, content with the murder of his ex-pupil, Ben, Gwen, and Kevin are met with a horrible sight when they see Azmuth's frail body lying motionless on the ground below them.
Ben picking Azmuth up and cradling him in his arms, the Galvan stirs very briefly, using his remaining strength to upgrade the Ultimatrix into the Infinity Matrix. Azmuth then tells Ben he is on his own when the boy asks how he's supposed to use the upgraded device, but that he always knew Ben would do great things with it. Azmuth says his final farewell to the trio and tells Ben the Infinity Matrix will give him the power he needs before fading out of existence in a flash of light.
- Creators stated that they were originally unsure of a traumatic event that could serve as some of Ben's motivation to defeat The Master. They selected Azmuth's death to serve as this event, as the character was not necessarily needed to continue the story, yet he was important enough to cause an emotional reaction from audiences. This death was originally scripted to happen much later in the Aliens Unleashed series, but it was pushed up to the first two episodes of the series in order to get the show moving more quickly.
- It has been confirmed that while Azmuth's thoughts and ideals still live on in Ben and will be demonstrated periodically, he will return physically in some way.