Pokémon Scarlet and Violet The Indigo Disk doesn’t focus too much on new Pokémon, but a few species debut in Blueberry Academy. This includes the transformation of the skyscraper-like Duraludon into its bridge-inspired evolution, Archaludon.
Archaludon is the only evolution of Duraludon, which was previously a single-stage Pokémon introduced in Sword and Shield. Less than a generation later, it has received a big power boost, and you can easily obtain the item needed to reach this new form.
How to evolve Duraludon Pokémon Scarlet and Violet The Indigo Disk
Since Duraludon was previously a single Pokémon evolutionary line, it appears Game Freak took into account how players might already have a well-trained Duraludon ready to transfer over. Instead of needing to level your Dragon/Steel-type up, use a new Evolution Item, the Metal Alloy to get an Archaludon.
The Metal Alloy can be obtained in a few different ways. The easiest way is by saving up 300 Blueberry Points (BP) and heading to the School Store in Blueberry Academy. You can also find the item while exploring the Terarium—with one having a specific spawn point in the Chargestone Cavern.
Once you obtain a Metal Alloy, go into your bag and select “Use” before clicking on a Duraludon in your party. This will instantly cause it to start evolving into Archaludon. This should also give you access to new moves like Electro Shot since it is set to be learnable directly upon evolution.
You can find Duraludon in the wild frequently as you explore the Terrarium, so you don’t need to struggle with encountering one as long as you look in the right biome.