Rhydon can be evolved into Rhyperior without having to trade in Pokémon Legends: Arceus. Players will need to save up Merit Points to buy the evolution item from the Trading Outpost in Jubilife Village in order to evolve Rhydon. Before completing the evolution, players will need to either catch Rhydon or catch and evolve Rhyhorn in Pokémon Legends Arceus. Rhyhorn can be found fairly early on in the game, but players will need to progress to Coronet Highlands to find Rhydon.
For players that want to get Rhyperior as soon as possible, they can catch Rhyhorn in Pokémon Legends: Arceus' Crimson Mirelands, which is the second area that can be accessed. Rhyhorn can spawn in Bolderoll Slopes, Diamond Heath, and Shrouded Ruins. Later in the game, players can also catch Rhyhorn in Coronet Highlands' Celestica Trail and Sacred Plaza. To evolve Rhyhorn into Rhydon, players will need to level it up to 42.
To avoid battling and gathering resources using Rhyhorn to evolve it, players can search for Rhydon in Celestica Trail and Sacred Plaza in Coronet Highlands. Once players have a Rhydon, they don't need to worry about leveling it up. Instead, Rhydon evolves using a Protector, which players can purchase from the Trading Outpost in Jubilife Village. In order to purchase the Protector, players will need to earn Merit Points or find it randomly while exploring.
Evolving Rhydon into Rhyperior in Pokémon Legends: Arceus
Merit Points can be earned from the Lost and Found system which can be accessed through the menu. Players will need to find Lost Satchels that were dropped by other trainers who were knocked out around Pokémon Legends: Arceus' Hisui region. When a Lost Satchel is interacted with, the contents will be returned to the owner automatically. Players can then access the Lost and Found menu to claim Merit Points for each Lost Satchel they return.
To evolve Rhydon, players will need to collect a total of 1,400 Merit Points and purchase the Protector evolution item. When players have enough Merit Points, they can access the Trading Outpost in Pokémon Legends: Arceus' Jubilife Village and buy the Protector. Alternatively, players can try to find a Protector in a Space-Time Distortion Zone, but there's no guarantee it will be available to find. As soon as Rhydon is given the Protector item, it will be ready to evolve into Rhyperior.
Adding Rhyperior to a team can give players a powerful Ground- and Rock-type Pokémon to battle with in Pokémon Legends: Arceus. Rhyperior also has a chance of spawning in the Sacred Plaza in Coronet Highlands, but it has a low spawn rate, so it may be easier for players to evolve it from Rhydon. In Pokémon Legends: Arceus, Rhydon is one of several Pokémon that can only be evolved using a special evolution item from the Trading Outpost.
Pokémon Legends: Arceus is available for Nintendo Switch.