Ultraman Dyna aired between 6 September 1997 until 29 August 1998. The series is a direct sequel to the previous Ultraman series, Ultraman Tiga.
In the year 2017 (9 years after the final episode of Ultraman Tiga), TPC has advanced beyond earth, and has created a new GUTS team, “Super GUTS”. Humans have begun terra-forming Mars and other planets in what is known as the “Age of the Neo Frontier”. One day, however, the Neo Frontier is attacked by an alien race known as the Spheres. Shin Asuka has just joined Super GUTS and is in the middle of training manoeuvres above Earth’s atmosphere when he and his comrades are attacked. He proves himself in battle, and can hold his own against ace pilot Ryoh. However, his ship is damaged and he ejects, after which he encounters a shining light. It is then that a new giant of light merges with the bewildered Asuka, saving his life. When the Spheres enter Mars’ atmosphere and merge with the Martian rocks to form monsters, Asuka again participates in the battle, now equipped with a mysterious device known as the “Reflasher”. Upon the Sphere’s new attack, Asuka suddenly transforms into a colossal giant, and manages to protect Mars from a group of monsters sent by the Spheres. The members of Super GUTS quickly catch on that this giant being is not Ultraman Tiga, but a new giant of light, “Ultraman Dyna”. In contrast to the serious tone of Ultraman Tiga, Ultraman Dyna is a far more light hearted show, featuring more upbeat stories and comical character personalities for its cast.
The final story arc is rather somber, in contrast to the rest of the series. Dyna/Asuka apparently sacrifice themselves to save the Earth from Gran Sphere, the planet-sized mother form of the Spheres. In the series finale, we do get to see that Asuka rejoins his father as they ride off toward the light in their two spaceships, though the fate of Dyna / Asuka and Asuka’s father remains unknown. Eleven years after the end of the television series, the movie Mega Monster Battle: Ultra Galaxy is intended as a direct follow-up for Dyna / Asuka after events of the Dyna series finale. It is revealed that the wormhole resulting from Gran Sphere’s destruction transported him to the M78 universe, where the film takes place. At the end of the movie, as the featured ZAP SPACY members require help back to Earth, Dyna / Asuka decides to direct them home personally. They are shown disappearing into a self-made wormhole together.
Upon the conclusion of Ultraman Saga, Asuka contacts SUPER GUTS while traveling to an unknown destination. He assures them that Taiga is alive and well, as Ryo responds that they will catch up to Asuka one day, Asuka smiles and says that he will wait for them before vanishing into the light once more.
It is unclear if the Dyna that participated in the Dark Spark War in Ultraman Ginga is the same Dyna from the Tiga Universe.