Early Regulation M-C: Rillaboom and the Changing Metagame

Introduction

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Regulation M-C has arrived in Pokémon Champions. The new additions include terrain setters such as Rillaboom and Indeedee, Mega Salamence, Mega Golisopod, Mega Baxcalibur, and Z Mega Evolutions for Absol, Garchomp, and Lucario. How are these new Pokémon and held items changing the teams that developed throughout M-B? Official regulation announcement · New Pokémon and held items

This column examines 25,987 battles collected from September 9 at 11:51 UTC to September 12 at 10:54 UTC, using the M-C report updated on September 12, 2026, at 11:01 UTC. Our comparison is the final M-B sample: 119,958 battles from August 27 to September 9. That is a different reporting window from our August 27 column, so the M-B figures here differ from those in the earlier article. M-C Tier List · M-B Tier List

Figures in this article reflect the reporting snapshot described above. The linked M-C Tier List is updated daily, so its current figures may differ from those cited here.

This is still a snapshot of roughly three days on the Pokémon Showdown ladder. The average rating is also different: 1196 in M-C, compared with 1311 in M-B. These comparisons do not track the same group of players, and the results may differ from official Pokémon Champions tournament play. Win rates measure the results of teams containing each Pokémon, rather than that Pokémon's isolated contribution. Methodology

Rillaboom Reshapes Terrain and Turn Order

Rillaboom is the most widely used newcomer. At 41.07% usage and a 51.26% win rate, it enters Tier A and is already a central consideration when building for the format. M-C Tier List

Its role extends well beyond strong Grass-type attacks. Rillaboom combines terrain control through Grassy Surge, support through Fake Out, priority through Grassy Glide, and pivoting through U-turn. The ability to pressure opponents while creating opportunities for teammates helps explain why it fits into so many different teams. Rillaboom's moves and abilities

Among returning Pokémon, Sneasler shows a particularly noticeable increase in usage, rising from 25.69% in M-B to 39.05% in M-C, second only to Rillaboom. Its win rate, however, moves from 51.06% to 50.63%. Wider adoption has not translated into a higher overall win rate. M-B Tier List · M-C Tier List

The newly available Grassy Seed and Psychic Seed are important additions here. Consuming a Seed on its corresponding terrain gives Sneasler a way to activate Unburden, and public teams already pair Rillaboom with Grassy Seed Sneasler. This is an example of new held items opening up another approach for an already established Pokémon. Our Tier List does not, however, isolate the win rate of Seed sets. New held items · Public team examples

The other prominent new terrain setter, Indeedee-F, has quickly reached 22.13% usage, although its 49.40% win rate places it in Tier C. Male Indeedee sits at 6.06% usage and a 50.97% win rate. The two are tracked separately and should not be treated as interchangeable roles. M-C Tier List

Psychic Terrain protects grounded Pokémon from opposing priority moves, while Rillaboom can replace that terrain. This contest changes when teams can safely rely on Fake Out and other priority attacks. Yet Indeedee-F's popularity has not brought every associated attacker to the top: Armarouge has a 48.16% win rate, and Hatterene sits at 48.31%. Maintaining terrain and finding a plan after it is replaced still look like areas with room for refinement. M-C Tier List

Pawmot also brings a new option through Revival Blessing, which can revive a fainted teammate. So far, it has 6.15% usage and a 49.78% win rate, placing it in Tier D. Having a distinctive tool has yet to produce consistently strong results across the teams using it. New moves · M-C Tier List

Different Starts for the New Mega Evolutions

Among species receiving a newly available Mega Evolution, Salamence has made the strongest start. With 29.12% usage and a 52.17% win rate, it joins Rillaboom in Tier A and is already central to the early format. M-C Tier List

Mega Salamence's Aerilate turns Normal-type moves into Flying-type moves and boosts their power. Access to spread damage through Hyper Voice and speed control through Tailwind is attractive on a Pokémon that can pressure Rillaboom and Sneasler while helping its teammates. It can threaten opposing Rillaboom while also serving as an offensive partner for Rillaboom on its own team. That flexibility offers a plausible explanation for its broad early adoption. Mega Salamence's ability and moves

Golisopod is also popular at 24.82% usage, but its 50.13% win rate places it in Tier B. It has made an immediate impact on team building, although its overall results have not separated it from the field as clearly as Salamence's. M-C Tier List

Mega Golisopod nevertheless has some appealing qualities in this environment. Its Bug/Steel typing gives it a quadruple resistance to Grass-type attacks, while rain reduces the damage from Fire-type attacks, its only type weakness. Those traits make it a natural candidate for the Pelipper and Archaludon teams discussed below. Mega Golisopod's typing and resistances

Other species with newly available Mega Evolutions have had a more difficult start.

Source: M-C Tier List.

These are species-level results, not results for the newly added Mega forms alone. In particular, the figures for Garchomp, Lucario, and Absol do not distinguish their existing forms from their Z Mega Evolutions. Garchomp's 49.34% should therefore not be described as Mega Garchomp Z's win rate. The same distinction applies to Salamence and Golisopod: the listed figures cover all teams containing the species.

With that distinction in mind, the early pattern is still clear. Salamence and Golisopod have quickly found broad adoption, while teams containing several other new Mega candidates have yet to post strong overall results. More refined sets and team structures may change that picture as the format develops.

Archaludon Stands Out in New Rain Teams

New Pokémon naturally attract attention at the start of a format, but one returning Pokémon deserves particular focus: Archaludon. In the final M-B sample, it occupied Tier B with 10.55% usage and a 51.81% win rate. In M-C, it reaches Tier A with 11.96% usage and a 55.31% win rate, the highest among Pokémon included in the report. M-B Tier List · M-C Tier List

The change in results is more striking than the change in usage. At the archetype level, the group containing Archaludon + Golisopod + Pelipper + Rillaboom has a 57.16% win rate across 1,340 recorded team appearances. The five-Pokémon group that adds Farigiraf also performs well, with a 54.98% win rate across 673 appearances. M-C archetypes

Rillaboom's arrival creates new challenges for Water-types, but it is too early to conclude that rain teams as a whole are worse off. Around Pelipper's rain, Archaludon and Mega Golisopod provide Grass resistances, and Rillaboom itself can join as a teammate. This kind of restructuring looks like a promising early direction.

Golisopod's overall win rate is close to 50%, yet this four-Pokémon group performs much better. It illustrates why looking at successful partners can add useful context to a species' overall results. The four- and five-Pokémon groups overlap, however, so their appearance counts cannot be added together as independent evidence of success. These are recorded team appearances, not counts of unique players or distinct builds.

Swampert is another strong performer, with a 55.15% win rate at 4.00% usage. Water-types are still finding success in a format full of Rillaboom, a useful reminder that type matchups alone do not determine metagame results. Swampert's narrower usage makes the players and builds behind those results particularly worth following. M-C Tier List

Where Do M-B's Leading Pokémon Stand Now?

Comparing the final M-B sample with early M-C reveals several distinct changes among the established names.

Sources: M-B Tier List and M-C Tier List. The samples cover different periods and have different average ratings.

M-B's two Tier A Pokémon, Kingambit and Basculegion, both move to Tier B. Even so, each remains on roughly a quarter of teams, with win rates in the upper 51% range. Both continue to feature in successful early M-C structures.

The group containing Kingambit + Rillaboom + Salamence + Sneasler has a 54.54% win rate across 2,466 recorded team appearances. Adding Basculegion gives a five-Pokémon group with a 54.94% win rate across 1,103 appearances. The full six-Pokémon composition that also includes Arcanine-Hisui reaches 56.48% across 579 appearances. As with the rain groups, these are overlapping structures. M-C archetypes

These results show established M-B Pokémon forming successful teams with new partners. That is a useful way to understand Kingambit and Basculegion's current position. Building around them with M-C's additions may offer different possibilities from bringing an M-B team forward unchanged.

Garchomp, Staraptor, and Whimsicott, by contrast, have declined in both usage and win rate. Competition with Salamence for team slots is one possible factor for Garchomp and Staraptor. For Whimsicott, new offensive Tailwind users and Seed + Unburden offer other ways to manage speed. These are hypotheses based on overlapping roles; the aggregate figures do not establish the causes of the declines.

Charizard tells a different story. Its usage has more than halved, but its 52.25% win rate is close to the final M-B figure of 52.17%. Its Tier has fallen, yet the teams using it have maintained a similar win rate. As players explore new Mega options, Charizard's continued performance is worth keeping in view.

Floette-Eternal also shows relatively modest declines in usage and win rate, remaining in Tier B. Meanwhile, Staraptor, Raichu, and Sylveon, which formed a successful M-B team family, have all lost usage. The structures highlighted in our previous M-B analysis will not necessarily retain the same prominence in M-C.

Among support Pokémon, Incineroar gains usage and rises to Tier B. Rillaboom has not simply taken its place: teams containing both, alongside Salamence and Sneasler, appear among the major archetypes. A new support option is also creating opportunities to use established support Pokémon alongside it. M-C archetypes

What to Watch as Teams Develop

Beyond rain, Excadrill is also posting strong results, with 5.61% usage and a 54.97% win rate. Tyranitar reaches a 52.93% win rate, while the five-Pokémon group containing Excadrill + Indeedee + Salamence + Sneasler + Tyranitar records 55.51% across 726 team appearances. Established weather structures are finding ways to incorporate new terrain setters and attackers in more than one part of the metagame. M-C Tier List and archetypes

In this early sample, Rillaboom and Salamence have attracted broad adoption, while Archaludon stands out through its win rate. Around them, rain teams incorporating Golisopod and structures retaining Kingambit and Basculegion are already producing strong results.

We will be watching whether Salamence can maintain both its popularity and performance, whether Golisopod can build on its successful team structures, and whether the slower-starting Mega candidates find more effective roles. How M-B's established teams incorporate new terrain options and Mega Evolutions should be one of the most interesting developments to follow. M-C is only just beginning, and there are still plenty of combinations to explore.

See you in the next column.