Galarian Yamask’s evolution method in Sword and Shield is one of the strangest and most confusing in the history of the Pokémon franchise. Thankfully, we’ve put together a guide to make things a little clearer on how-to evolve Yamask into Runerigus in these games!
Step One: Catch a Yamask
Yamask’s not too difficult to find – you’ll probably bump into a few on Route 6 between Stow-on-Side and Hammerlocke, where they’re active in all weather conditions. The only requirement for evolving these Yamask into Runerigus is a HP stat of at least 50, and the level 30+ Pokémon on Route 6 fulfill this condition neatly. A Quick Ball or Great Ball should be all you need to catch one.
Step Two: Go to the Dusty Bowl
The next step is where it gets a little odd – you’ll have to head to the Dusty Bowl zone within the Wild Area, and make your way over to the biggest of the stone arches (pictured above).
Step Three: Weaken your Yamask
To evolve into Runerigus, Yamask needs have taken at least 49 points of damage. This damage has to come from enemy attacks – you can’t speed up the process by using Curse to lower your own HP! There are plenty of wild Pokémon here that can deal damage to Yamask, but remember that you don’t want to let it get knocked out. There’s also no point in battling the many wild Electrike here, as they won’t be able to damage Yamask with their Electric-type attacks.
Step Four: Walk under the arch
After Yamask has taken 49 or more damage to its HP, it’s ready to evolve. Keeping Yamask at the front of your party, walk under the large stone arch. You’ll be stopped by a notification as you pass beneath it, and the evolution cutscene will begin. If you’ve followed all the steps correctly, you should now have a Runerigus!