Beating the Elite Four and becoming the next Pokémon Champion has never been the only goal of the Pokémon games — you’ll also want to catch every Pokémon fill out your Pokédex, and Brilliant Diamond and Shining Pearl are no different. Normally you can find Pokémon throughout the world or by trading version-exclusive Pokémon. However, some Pokémon require special methods to evolve or items to evolve. Magmortar is a great example of a Pokémon that needs a few extra steps to evolve, so let’s get into how it’s done.
Magmortar is the last of the Magby evolutionary line; as such, you’ll need a Magby, which is a little difficult to catch. It’s also a Pokémon exclusive to Shining Pearl, so Brilliant Diamond players will need to rely on trading in order to complete the Magby line. Your next step is to get a Magmarizer.
The Magmarizer, like Magby, is exclusive to Shining Pearl. Thankfully it’s not too hard to find. Once you have the Magmarizer, give it to your Magmar as a held item. The next step in this process will require the help of a friend you trust.
Start a trade with your friend and send over your Magmar while it’s holding the Magmarizer and it will evolve into Magmortar. Now have your friend send Magmortar back over to you. Try to trade with a friend who’s playing Brilliant Diamond so both of you can fill out your Pokédex at the same time.