Eternatus is one of the strangest and most powerful Pokemon in the long-running series, but it has a lot of mystery around it. The poison-dragon dual-type Pokemon has a pair of unique moves that can’t be learned by anyone else, and has unique mechanics that can’t be found elsewhere.
So how do you catch Eternatus? How does it stack up against other legendary Pokemon? And just what the heck is Eternatus supposed to be?
Eternatus is captured by defeating it in the Energy Plant during the story of Pokemon Sword and Shield. It must be captured in order to beat the game, and it is actually impossible to avoid capturing it after defeating it in battle.
After obtaining all eight badges and besting Bede, Marnie, and Hop in the endgame championship, the player is forced to go into battle with Pokemon League staff and Chairman Rose. This leads to a battle with the Eternamax version of Eternatus alongside Hop, Zacian, and Zamazenta. Once Eternamax Eternatus is defeated, the trainer is forced to catch it, and there is no way to avoid doing so.
Eternatus is guaranteed to be captured no matter what Pokeball is thrown, and a Pokeball is added to the trainer’s inventory at the start of battle if they do not already have one available. On top of that, the 32nd box in the trainer’s PC is opened after the battle, guaranteeing that there is space for Eternatus even if the player’s boxes and party were already full.
It is unclear what Eternatus is meant to be based upon, but there are some interesting theories that do make sense.
Eternatus has an origin story similar to Deoxys, coming to Earth on a meteor millenia ago. This has many thinking that Eternatus is a sort of viral rival to Deoxys, which is further shown by their opposite designs with Eternatus being sharp and angular while Deoxys is flowing and rounded. Eternatus’ Eternamax form also has a similar appearance to some viruses.
Another theory is that Eternatus is this universe’s answer to Necrozma, the prism Pokemon. Both inherently absorb energy and have designs that are harsh and polygonal. This is less likely, given that Necrozma is already linked to fellow Sun and Moon legendaries Solgaleo and Lunala, but there are definitely similarities there.
The Eternamax version of Eternatus is the strongest Pokemon in the history of the series. It has 1,125 combined base stats, almost double the 600 base stats enjoyed by mythical and pseudo-legendary Pokemon such as Mew and Tyranitar.
Those stats give Eternamax Eternatus base HP as high as Blissey, with defenses that are even stronger than those of Shuckle. He also still has attack and speed stats that are comparable with other legendary Pokemon.
Alas, players do not get to use the Eternamax version of Eternatus without the use of hacks. Once Eternatus is captured, he reverts from the Eternamax form and is incapable of Dynamaxing.
Not counting alternate versions of Pokemon, Eternatus still has the highest base stats of any Pokemon. The regular version of Eternatus has 690 base stats, which is higher than almost any other legendary Pokemon who normally have between 660 and 680 base stats.
Alternate versions of some legendary Pokemon have higher base stats than Eternatus. Most of these can only be activated in battle, which is the case with crowned Zacian and Zamazenta and Complete Forme Zygarde. The only Pokemon that has stats that are better than Eternatus outright are the Black and White versions of Kyurem at 700 base stats.