"Once a year, on a specific date and at a specific time, they gather out of nowhere and form up in a circle," Stonjourner's Pokédex entry. Could you even imagine how terrifying that would be if their meeting place was like... your house? Imagine waking up to that. Or, better yet, hearing their footsteps quickly surround you. Yeesh.
Locating Stonjourner
Regardless, you're here to catch Stonjourner. Well, if you have Pokémon Shield, you turn yourself right around and walk on over to the GTS, as Stonjourner is a Sword exclusive Pokémon!
If you're playing Sword and looking to catch Stonjourner, you have a couple of different options on where to do so. To start, Stonjourner can be found through Max Raid Battles in Giant's Seat, Rolling Fields, and Stony Wilderness. Otherwise, every location that you can find Stonjourner in is going to be through a non-overworld encounter.
Outside of the Wild Area, Stonjourner can be found on Route 10 at a 2% encounter rate. The only other place you'll find Stonjourner is the Lake of Outrage, with a 2% rate under intense sun and a 5% rate in a sandstorm. Yeah, no matter what way you cut it, Stonjourner is an incredibly difficult Pokémon to find. Although, you don't have much ground to cover, so just stick to one area and start encountering. You're bound to find one eventually.
Rocky Boi Fight Time
Once you actually catch Stonjourner, that's really it. The Pokémon doesn't have an evolution or Gigantamax form. Of course, it can Dynamax like every other Pokémon out there. Still, that doesn't mean that it can't hold its own.
Well... it actually can't. That is, if it's going in against a special attacker. Its special stats are absolutely dreadful, but its physical stats are incredibly high, making this an off-balance Pokémon, to say the least. If you do plan on using Stonjourner, standby moves like Earthquake will do the trick. If you really want to be a competitive beast, use it to set up Stealth Rocks and give it a Focus Sash in order to keep it around for longer than it would normally survive. Its ability powers up all the attacks of its allies, so Stonjourner might be well-suited to double battles.