In the Crown Tundra you’ll find yourself on a legendary expedition to discover the secrets of the Legendary Giants. This adventure will task you with investigating multiple temples throughout the Crown Tundra seeking what lies inside.
Registeel
Head to the Giant’s Bed to locate the temple. Make your way up the stairs and interact with the door to receive the following riddle: “Let ring the piercing note that will wake the giant of steel.” To unseal the door, you will need to whistle (while off the bike) by pressing the L3 button on your controller. With the door open, head inside to reach the Iron Ruins. Step on the circles on the ground causing them to glow. When all seven circles are activated, the statue in the back of the temple will activate. Interact with it to start the encounter with Registeel.
Regice
Make your way to the Snowslide Slope in the central part of the Crown Tundra. Locate the temple and interact with the door to receive the following riddle: “Walk together with a living crystal of snow.” To unseal this door, you will need to catch a Cryogonal and set it as the first Pokémon in your party. Head through the doorway to enter the Iceberg Ruins. Step on the circles on the ground causing them to glow. When all seven circles are activated, the statue in the back of the temple will activate. Interact with it to start the encounter with Regice.
Regirock
Travel to the eastern part of the Giant’s Bed just north of Lakeside Cave to locate the temple. Interact with the door to receive the following riddle: “Let the first Pokémon hold a never-changing stone.” To unseal the door, you will need to equip an Everstone to the first Pokémon in your party. Head through the doorway to enter Rock Peak Ruins. Step on the circles on the ground causing them to glow. When all seven circles are activated, the statue in the back of the temple will activate. Interact with it to start the encounter with Regirock.
Regieleki / Regidrago
Head to Three-Point Pass south of the Frigid Sea in the eastern part of the Crown Tundra to locate the temple. To unseal the door, you will need to have Registeel, Regice and Regirock in your party. Before heading inside, make note of the two symbols on the outside of the temple. You will need to choose at this point whether you want Regieleki (yellow side) or Regidrago (purple side). Head through the doorway to enter Split-Decision Ruins. Step on the circles with your chosen pattern to cause them to glow.
When all the circles are activated, the statue in the back of the temple will activate. Interact with it to start the encounter with Regieleki or Regidrago. Once you have captured Regieleki or Regidrago, return to Peony at his camp base in Freezington to turn in the expedition.