There are plenty of returning Pokémon legendaries that you can capture in Pokémon Sword and Shield’s Crown Tundra expansion. You can attempt to capture them in the Dynamax Adventures or by playing through the game’s story. These legendaries are not the only returning faces you see. Oleana, the secretary to Chairman Rose and the antagonist of the game, returns, and you can find her in the Crown Tundra region.
The trick to having her appear is to speak to Peonia multiple times. You can find her in the Max Lair in the Slippery Slope area. Head inside, and speak to her multiple times. She’ll talk about a long-haired woman who visits a grave night after night, searching for something around it. You may have to finish several of the legendary adventures in the story before Peonia makes this reference.
The grave Peonia is speaking about is the one to the south of Giant’s Bed. Head over to it on your bicycle to investigate it.
Head over to the cemetery, and you should find Oleana standing over a grave next to a den. Start talking with her, and a cutscene will trigger. It’s a small little nod to the original portion of the game, and it’s fun to see added to the expansion. After the cutscene ends, you’re free to continue with your Crown Tundra adventure.