This is the second quest you’ll receive from Peony when you visit him at Freezington. To start the quest proper, you need to approach one of the four ancient ruins related to the Regi Pokémon. There are two located in the Giant’s Bed–one nearer Freezington and another in the opposite corner.
There’s a third ruin along Snowslide Slope, to the west of the tunnel to the Crown Tundra. If you completed the first quest, you may have gone past this ruin. Finally, there’s a ruin at Three-Point Pass, accessible via Roaring-Sea Caves and Frigid Sea. This one requires the upgrade for the bike that lets you cross water.
Here’s what you can find in each ruin:
- Iron Ruins: Registeel
- Rock Peak Ruins: Regirock
- Iceberg Ruins: Regice
- Split-Decision Ruins: Regieleki/Regidrago
You can head for any of the ruins, but you may want to save the fourth one for last. Because you can’t do anything there until you’ve visited the three other ruins. That said, when you inspect the door of each ruin, they will become a landmark so you can use the flying taxi to instantly return there. So you’re not losing much by going there.
When you go to your first ruin, Peony will call you and you’ll get the ridiculously camp splash image, letting you know the quest has started.