Regirock resided on the Island Cave, to where Glacia was going to. Meanwhile, Steven had a blind boy try to decode the slab that spoke how to awaken Regirock, Regice and Registeel. However, the blind boy failed to decode a part of the slab that was missing. The Elite Four struggled to awaken the Legendary Golems by attacking them. Fortunately, Sapphire came to Steven with his father's letter, where it was mentioned a Relicanth and a Wailord were required to summon the Legendary Golems. Sapphire used her Relo and Lorry, which emitted beams that awakened the Legendary Golems.
The Elite Four, as well as Steven and Wallace, teamed up with the Legendary Golems. Together, they stood around Sootopolis City to stop Groudon and Kyogre's collision from spreading throughout Hoenn. Glacia was with Phoebe atop Regice. However, despite the Legendary Golems halting the collision, the energy from Sootopolis City rose up into air. After Kyogre and Groudon were banished away from Sootopolis City, Steven took a major strain and died from controlling the Legendary Golems, who fled, with their mission over.
Before Emerald took on the Battle Pyramid challenge, Brandon sent out his Regi Pokémon he'd use in the battle, once Emerald climbed the pyramid a certain number of times. The reporter commented even if Emerald did succeed climbing the pyramid, he would have low chances at defeating Brandon's mythical Regi Pokémon. After his Registeel was defeated, Brandon sent Regice to battle Emerald's Cubone. A Jirachi appeared in the sky, making Brandon take a look at it during the battle. After being reminded by Emerald about the battle, Brandon's Regice fired Blizzard, which defeated Cubone. However, Sceptile, on whom Emerald used a Revive, recovered and defeated Regice with Iron Tail, which amazed Brandon at such a brave strategy. While facing Guile, Brandon had Regice use Blizzard. However, Guile waved his sword and repelled all attacks away from the Frontier Brains.
While speaking to Noland, Brandon juggled his Poké Balls, containing Regirock, Registeel and Regice.
Brandon's Regice intimidated Team Aqua and Magma admins; they wanted to know where Zinnia was, but the admins replied she didn't say where she went to.
|Superpower||With a Spoink in Your Step I|
|Blizzard||Skirting Around Surskit I|
|+ indicates this Pokémon used this move recently.*|
- indicates this Pokémon normally can't use this move.
- ^ RS071: The Beginning of the End with Kyogre & Groudon XIII
- ^ RS072: The Beginning of the End with Kyogre & Groudon XIV
- ^ RS073: A Royal Rumble with Regirock, Regice and Registeel I
- ^ RS074: A Royal Rumble with Regirock, Regice and Registeel II
- ^ RS075: With a Spoink in Your Step I
- ^ RS076: With a Spoink in Your Step II
- ^ RS080: It All Ends Now I
- ^ RS081: It All Ends Now II
- ^ RS084: It All Ends Now V
- ^ RS085: It All Ends Now VI
- ^ EM001: Never Spritz a Knotty Sudowoodo
- ^ EM009: A Dust-Up With Dusclops
- ^ EM010: Chipping Away at Regirock
- ^ EM011: You Need to Chill Out, Regice
- ^ EM013: Skirting Around Surskit I
- ^ EM016: Sneaky Like Shedinja II
- ^ ORAS017: Omega Alpha Adventure 16