The final challenge in Pokémon Legends: Arceus is capturing the God of the universe itself. Arceus is known to be the creator of all things in the Pokémon universe. Making its debut in Pokémon Diamond and Pearl, Arceus never actually got an official release. A Mystery Gift event was supposed to happen where trainers would obtain the Azure Flute item. After going to the top of Mount Coronet and playing the Azure Flute, Arceus will appear and the player can capture it. Since the event never happened, there was no way to get the Azure Flute without hacking the game. Now in Pokémon Legends: Arceus, it acts as the final secret boss of the game.
At the beginning of the journey, players find an Arceus Phone located near where they awaken. Throughout the story, the Arceus Phone will provide expositional text and open up pathways to find legendary Pokémon. For example, this item will open up the cave doors hiding the legendary lake trio. The game tasks the player with capturing all the Pokémon from the very start. Completing this challenge is how trainers can find Arceus.
In order to find and capture Arceus, trainers will need to catch all 240 Pokémon in the Hisui Pokédex. This does not include getting the legendary Pokémon Darkrai or Shaymin, two creatures that were given to players for having save files to other Pokémon titles. Fortunately, the Pokédex only requires the player to register the Pokémon by capturing it. There is no need to get every Pokémon to Research Level 10. After doing this, speak with Professor Laventon and he will task the player to visit the Temple of Sinnoh.
Capturing Arceus in Pokémon Legends: Arceus
The Temple of Sinnoh is the location where the final battle takes place during the main campaign. Upon entering the temple, play the Azure Flute and Arceus will appear. This won't be a traditional Pokémon battle either as gameplay is similar to facing against the other noble Pokémon. Trainers will need to use balms on Arceus to bring down its HP. Once the battle is over and Arceus is defeated, it will automatically join the player's party. Although if their party is full, it will go straight to the pasture instead.
Now that Arceus is available, trainers can give it one of its many plates. Throughout the story, the player has been rewarded with Arceus Plates for calming down the noble Pokémon. If a plate is given to Arceus as a Held Item, it will transform into that typing. For example, giving Arceus the Fist Plate will change its typing into a Fighting-type. Collecting every plate is the best way to keep Arceus as versatile as ever.
Pokémon Legends: Arceus is available now on Nintendo Switch.