>>41678205>Darkest Day20,000 years ago, a meteorite containing Eternatus crashed. Eternatus contains a seemingly infinite amount of energy that causes other Pokémon to Dynamax. This event is known as the Darkest Day, as the Dynamxed Pokémon went on a rampage and destroyed everything.
>Were there two trainers for the legendaries or was it just a "prophecy"My take on the "two trainers" was that there actually were two trainers and that Zacian and Zamazenta were their respective Pokémon (similar to how you and Hop each get Zacian / Zamazenta as your Pokémon). These fabled trainers would then go on to defeat and seal away Eternatus.
>Where did Dynamax come from?As centuries passed, Eternatus' seal began to wear away. As it cracks, small portions of Eternatus' energy escape, creating "Power Spots" throughout Galar that can Dynamax Pokémon. The Galar gyms and Wyndon Stadium were built upon these Power Spots.
There are also "Wishing Stars" containing Eternatus' energy. Professor Magnolia and Oleana used the Wishing Stars to create the Dynamax Band, which allows trainers to tap into Power Spots to Dynamax their Pokémon.
I don't think it's ever explained what the Wishing Stars were, but I assume they're fragments of the meteorite Eternatus came in.
>This guy was trying to save the future by destroying the present? Galar utilizes Wishing Stars to power the region, but Rose knew that one day they would run out. To prevent this, he wanted to free Eternatus and use its infinite energy. He had hoped Champion Leon would be powerful enough to capture Eternatus into a Pokéball, so that he (Leon) can control it and force it to give Galar its energy. Unfortunately, Leon was not strong enough to defeat Eternatus and it was up to you, Hop, Zacian, and Zamazenta to defeat it.