Eternatus

Eternatus is a Poison/Dragon-Type Pokémon in Pokémon Sword and Shield. Eternatus serves as the source of the Dynamax and Gigantamax phenomena in Galar due to its power leaking out in the form of Galar Particles following its defeat thousands of years ago by Zacian and Zamazenta. Pieces of its body imbued with its power rain down throughout Galar in the form of Wishing Pieces, Wishing Chips and Wishing Stars. When it is awake, Eternatus causes a phenomenon dubbed the Darkest Day, in which the massive quantities of Dynamax energy it unleashes causes Pokémon to Dynamax and rampage uncontrollably. Despite this, it cannot be Dynamaxed itself as its Eternamax form replaces that effect.

In its Eternamax form, Eternatus's power grows so immense that it causes a great storm of Dynamax energy around it, ripping holes in spacetime in the midst of the storm as it releases a virtually infinite amount of energy. Its tremendous power can even prevent opposing Pokémon from attacking it as it gathers energy.