In Sword and Shield: From Here to Eternatus!, Eternatus was revealed to have been captured by Macro Cosmos and placed inside the Energy Plant core. Rose planned to strengthen it with Galar Particles so it could serve as a source of infinite energy for the Galar region. In order to complete his agenda, Rose sponsored Trainers and specifically groomed Leon to become a modern-day hero figure who would ultimately subdue and catch Eternatus to ensure it could be kept as a power source. After a number of experiments in which Galar Particles were injected into the reactor, Eternatus escaped from its containment field within Hammerlocke Stadium.
Above the stadium, Eternatus began gathering massive amounts of energy from across the region, causing many Pokémon to Dynamax and Gigantamax and go on a rampage. Leon later tried to capture it with the help of his Charizard to seal away the Gigantic Pokémon but failed, and it subsequently turned into its Eternamax form. With the help of Zacian and Zamazenta, Ash and Goh defeated Eternatus, after which they threw one of Goh's Poké Balls at it together, catching it. After it was captured, the Dynamaxed and Gigantamaxed Pokémon returned to normal. Goh then had Eternatus's Poké Ball sealed away in a safe somewhere in Galar.