It’s time for another 7-star Tera Raid Event in Pokémon Scarlet & Violet, and this one features a Normal Tera Type Rillaboom. You’ll be able to challenge it until July 30, 2023 at 4:59pm PDT / 7:59pm EDT (23:59 UTC). As with the previous 7-star Tera Raid Events, this Rillaboom has the Mightiest Mark, granting it the title “Rillaboom the Unrivaled” when sent out in battle.
Before you can challenge Rillaboom, you’ll first need to have unlocked 6-star Raids, which is something you can do after beating the game and doing some of the postgame stuff. The Rillaboom raids will then appear in the Black Tera Raid Crystals on the map similar to the other 6-star Raid Crystals, though you’ll be able to tell it’s Rillaboom due to it being Normal Tera Type. Even if you don’t have it unlocked yet, you can still join other players if they have unlocked it and you have the Link Code or are playing with friends.
According to Serebii.net’s coverage, it knows the moves Drum Beating, Acrobatics, Body Slam, and Low Kick. It also has the additional moves Growth, Boomburst, and Bulk Up, which it uses at certain points throughout the fight. It also has the Ability Grassy Terrain, which is its Hidden Ability and sets up the matching terrain at the start of the fight.
If you’re looking for a guide for where to EV train your Pokémon to challenge Rillaboom, you can refer to Marriland’s Pokémon Scarlet & Violet EV Training Guides, which should help make your job easier by showing you which Pokémon to fight against to quickly and effectively EV train, although it’s up to you to decide which EVs and which Pokémon to use against Rillaboom.
After you’ve defeated it, you can catch it and you’ll be guaranteed to get an Ability Patch and TM066 (Body Slam) the first time you defeat it. You can catch it only once; after that, you can still fight it again to get rewards.
This is the first of two runs of this event. Rillaboom will appear a second time the following weekend, from August 3, 2023 at 5:00pm PDT / 8:00pm EDT (August 4, 2023 at 00:00 UTC) through August 6, 2023 at 4:59pm PDT / 7:59pm EDT, although you can still catch it only once per game.