The sheer success of Pokemon Brilliant Diamond and Shining Pearl's launch within three days and only considering Japan sales speaks volumes about how many players loved the original Generation 4 Pokemon games when they were released, 15 years ago. Be it veterans of the series or newcomers, there was something about Pokemon Diamond and Pearl, and then Pokemon Platinum, that marked Gen 4 as one of the best Generations to ever be released. There were many iconic moments in Generation 4 games that players can now relive through Pokemon Brilliant Diamond and Shining Pearl, even though one of the most quintessential ones is the fight against Arceus.
With Pokemon Legends: Arceus on its way in under two months, it's likely that more of the lore surrounding the God Pokemon will be revealed in the game. As for Pokemon Brilliant Diamond and Shining Pearl, players can't catch Arceus for the time being, even though a future update or event could unlock the Legendary Pokemon, possibly when the Pokemon Home compatibility goes live.
Arceus was originally given through an event tied to the official Pokemon movie called Arceus and the Jewel of Life, but some players managed to make a cheat engine for everyone to get the Legendary Pokemon. Arceus was encountered in the Hall of Origins when using the event-exclusive item called Azure Flute, and a Pokemon Brilliant Diamond and Shining Pearl fan remade the entire encounter, and Arceus' spawn location as their fan-made project. The video was shared on Reddit by its creator, a user by the name of AdrianMendezzGarcia, and it shows Pokemon Diamond and Pearl's female protagonist, Dawn, fighting Arceus with her Palkia and a frightened Piplup.
I created this reimagined Arceus encounter scene from Pearl and Diamond (This is a Concept/FanMade, not a videogame) from pokemon
Everything is spot on, even showing the original animation for the Azure Flute and the astral stairs appearing in front of players, leading them to Arceus. Then, the piece of art features a proper Pokemon battle in the style of Pokemon Brilliant Diamond and Shining Pearl, with the level 100 Palkia one-shotting Arceus with a Hydro Pump. However, Arceus then proceeds to Mega Evolve and uses its signature move, Judgement.
The fact that Arceus is absent from Pokemon Brilliant Diamond and Shining Pearl is a bit sad, considering its appearance was part of the original Generation 4 games, but all hope is not lost. In fact, Pokemon Brilliant Diamond and Shining Pearl potentially include a Pokemon Legends: Arceus teaser, thus the Legendary Pokemon might be either coming to the remakes in January or at least be available in its titular release.
Pokemon Brilliant Diamond and Shining Pearl are available now on Nintendo Switch.