Pokémon Champions is preparing to make its Ranked Battles considerably more Mega-shaped. Regulation Set M-C is scheduled to begin on Tuesday, September 8, 2026, at 7:00 p.m. PDT, and it is due to remain active until Tuesday, December 1, 2026, at 5:59 p.m. PST. The new ruleset follows its tease during the 2026 Pokémon World Championships and expands the available battle roster without removing Pokémon that were legal in earlier regulation sets.
That continuing eligibility is an important detail. Rather than asking players to abandon everything that worked before, Set M-C enlarges the competitive toy box. Existing Ranked Battle choices will remain part of the conversation while a group of newly introduced Pokémon and Mega Evolutions enter it. In other words, the metagame is getting a new wing bolted onto the house, and the old furniture has not been thrown into the street.
Pokémon Champions launched on April 8, 2026, as a battle game for Nintendo Switch, iOS, and Android. Its Regulation Set M-C update is built around a particularly attention-grabbing number: 24 Pokémon will become newly available for battle. The additions include Pokémon with prior significance in VGC competition, with Rillaboom specifically noted among them. That combination of a wider roster and returning tournament relevance gives players a clear reason to inspect the legal lineup instead of assuming this is simply a cosmetic Mega Evolution parade.
When Regulation Set M-C begins and ends
Players planning ranked sessions around the rollover should note that the start and end times use different Pacific time designations. The regulation period is listed as:
- Start: Tuesday, September 8, 2026, at 7:00 p.m. PDT
- End: Tuesday, December 1, 2026, at 5:59 p.m. PST
The dates place M-C across much of the autumn competitive calendar. It begins in daylight time and closes after the seasonal shift back to standard time, so anyone coordinating with teammates, tournament communities, or friends in other regions should convert the published times carefully. A one-hour mistake is not usually a devastating competitive tragedy, but it is exactly the kind of administrative side quest that can make a player stare at a clock as though it has used Protect three turns in a row.
Nothing in the stated format suggests that prior Ranked Battle-eligible Pokémon are being retired at M-C’s launch. The known arrangement is additive: Pokémon already eligible under previous regulation sets stay legal, and the new selections join them. That distinction should matter to players evaluating teams, because a broadening roster can create fresh combinations while preserving established options.
The Mega Evolution additions
Six Mega Evolutions are being added alongside the update. Three of the named additions are Mega Salamence, Mega Golisopod, and Mega Baxcalibur. Pokémon Champions will also receive three Z Mega Evolutions: Mega Absol Z, Mega Garchomp Z, and Mega Lucario Z.
Those names make the update easy to summarize but harder to reduce to a single style of play. Mega Salamence, Mega Golisopod, and Mega Baxcalibur bring very different identities to the roster on paper, while the Z Mega forms attached to Absol, Garchomp, and Lucario put further emphasis on several prominent species. The announcement does not provide move data, ability details, item interactions, stat spreads, or battle-specific mechanics for these forms. Players should resist filling those gaps with assumptions until the full in-game roster and its details can be checked.
Still, the broader point is unmistakable: Mega Evolution is not a minor footnote to M-C. Half of the identified Mega additions are Z Mega Evolutions, and all six are presented as part of the regulation’s central expansion. For a battle game that asks players to make roster choices, the practical next step is not merely recognizing a favorite Pokémon’s name. It is determining which options are actually selectable under the new regulation and how their presence changes the pool around them.
Rillaboom is among the newly available Pokémon
Rillaboom is specifically called out as one of the 24 Pokémon newly available in battle. Its inclusion is notable because it has made an impact in past VGC tournaments. That does not automatically establish what role it will hold in Pokémon Champions under Regulation Set M-C; previous competitive history is context, not a guaranteed forecast. Different available partners, game systems, and roster restrictions can all affect whether a familiar contender becomes a centerpiece, a useful specialist, or simply another tempting name on the recruitment screen.
Even so, its arrival signals that the new batch is not restricted to Mega Evolution headlines. M-C’s 24 added Pokémon encompass more than the six added Mega forms, leaving a larger collection for players to examine. The available information identifies Rillaboom as one such addition but does not publish the entire list in the announcement text. The game itself is the stated place to view the complete roster.
For collectors who move between cards and games, it is also a useful reminder that familiarity can mean different things in different Pokémon hobbies. A recognizable Pokémon may be a binder favorite, a rarity chase, a tournament staple, or all three at once—but those categories are not interchangeable. For a refresher on reading the collectible side of the hobby, see Pokémon rarity symbols and how to read them. Regulation Set M-C, however, is concerned with battle availability, not card rarity.
How to check the complete M-C roster in Pokémon Champions
Pokémon Champions includes a direct route for viewing the full roster. Rather than relying on partial lists or trying to reconstruct eligibility from old teams, players can use the Recruit menus:
- Open Recruit.
- Choose Recruit Pokémon.
- Select Roster Info.
- Open Pokémon Featured in This Roster.
This menu path is especially helpful given the scale of the change. With 24 Pokémon joining the battle pool and six Mega Evolutions arriving at the same time, a quick glance at the complete in-game list is a better starting point than building around only the names that made the first wave of headlines. It also provides the clearest way to verify eligibility as M-C goes live.
The roster screen should be treated as the practical reference point for players deciding what to recruit. That does not mean every newly available Pokémon will demand an immediate rebuild. It means the choices exist, and the first job is to understand the full field. A player with a favorite returning lineup may only need a few adjustments; another may find that one of the incoming options inspires an entirely different direction.
What the new regulation changes—and what remains unknown
The confirmed picture is straightforward. Regulation Set M-C runs from September 8 through December 1, 2026. Prior Ranked Battle-eligible Pokémon remain eligible. Twenty-four Pokémon are newly available for battle. Six Mega Evolutions join the game, including Mega Salamence, Mega Golisopod, Mega Baxcalibur, Mega Absol Z, Mega Garchomp Z, and Mega Lucario Z. Rillaboom is among the new battle options, and the full roster can be viewed through the Recruit menu.
There are also limits to what has been established. The announcement does not lay out a complete written roster, detailed rule document, matchup guide, tier list, or prediction for which Pokémon will dominate. It does not say that every newly added Pokémon will have equal competitive impact. It does not provide a reason to declare an early winner before players have even had time to inspect the legal selections.
That uncertainty is part of the fun of a regulation change. The first layer is obvious excitement over famous names and new Mega forms. The more useful layer is patience: check the roster, recognize that old legal Pokémon remain in play, and let the actual available pool inform recruitment choices. Pokémon Champions has set the board for a larger Ranked Battle field in M-C. From September 8, players can begin finding out which newcomers are merely flashy and which ones are ready to make the ladder feel very, very different.
And for anyone who enjoys Pokémon as both a competitive game and a collecting hobby, organization remains a virtue in either arena. Deck boxes and card binders may not help a Mega Garchomp Z win a battle, but the collector instinct to check the exact item before reacting is still sound. The same principle applies here: inspect the roster, confirm the regulation, then make the big decisions.
