Eternatus

Intro also known as the darkest day, controller of the dynamax phenomenon, the final boss of pokemon sword and shield, legendary pokemon, the most powerful pokemon in terms of base stat totals, when defeated it will enter its eternamax form where it becomes impossible to defeat without the help of Zacian and Zamazenta (i have made another eternatus themed talkie where the darkest day wasn't stopped so if you want to do that one look up eternamaxeternatus one word)