Magnezone is alive and well in Pokemon Sword & Shield with the launch of the Isle of Armor DLC. There are a couple of different ways to evolve Magneton into Magnezone. The new evolution relies on a Thunderstone, so you need one of those to carry it out.
And in case you’re on the hunt for Magnemite to start the evolution chain, they’re easy to grab. You can find it near the Water Tower, on Challenge Beach. They will be visible either near the cave in that area or by the river, just floating around chilling. They are going to be fairly high-level so keep that in mind. If you’re going to need to evolve it to Magneton, it does so at any point after you catch it, because it spawns on the Isle of Armor at level 60.
As for where to find the Thunderstone, there are two main ways to do that. The most common sources for this item are around the mainland. You may also still have the one from the base game. That one can be found on a small hill, inside the North Lake Miloch (Wild Area). In the north-east (top right corner) of that region lies the aforementioned hill.
The source within the Isle of Armor DLC relies on the dojo upgrades. You can unlock the Thunderstone as a purchasable item from the Dojo if you unlock the Rotomi Terminal upgrade for 10,000 Watts.
If you’re looking for more tips for the new Isle of Armor DLC for Pokémon Sword and Shield, we’ve got you. We have guides on how to get the EXP Charm. Where to go to find various rare items like the Armorite Ore. And for those competitive Trainers, learn how to get some great five-star Ditto for breeding too. You can also get Gigantamax forms of Squirtle or Bulbasaur as well. If you’re on the hunt for various Gen I spawns, head to the secret Brawler’s Cave for some nice spawns like Poliwrath and Lickitung.