Rain Team Guide — Pokémon Champions
Mega Swampert's Swift Swim, Pelipper's Drizzle, Basculegion's Last Respects — the three-way synergy that makes rain the most oppressive weather archetype in Regulation M-B. Builds, pilot strategy, and counter-play inside.
Why Rain Dominates Regulation M-B
Rain in Pokémon Champions stacks three simultaneous advantages: a 50% boost to Water-type moves, doubled Speed for Swift Swim users, and a 50% reduction to Fire-type moves. All three effects trigger the moment Pelipper enters the field, creating an instant offensive and defensive shift that few team archetypes can match.
Regulation M-B's return of Mega Evolution is what elevates rain from a strong archetype to the premier threat. Mega Swampert's base 150 Attack combined with Swift Swim speed doubling creates a Ground/Water Mega with both nuclear physical output and metagame-defining speed in a single slot — a combination impossible under previous rulesets.
What makes rain particularly resilient is its built-in answers to its own counters: Archaludon threatens Grass-types with an instant-fire Electro Shot, while Basculegion's Last Respects actually powers up whenever opponents trade favorably. Shutting down rain is far easier said than done.
The Core Trio: Role Breakdown
Mega Swampert
Water / Ground · Swift Swim · Mega Evolution
Upon Mega Evolving, instantly gains Swift Swim, doubling Speed under Pelipper rain. Base 150 Attack lets Earthquake pressure both opponents simultaneously, while Wave Crash serves as a rain-boosted nuke. Ice Punch handles Grass-types and Dragon-types that would otherwise wall the team.
Pelipper
Water / Flying · Drizzle
Drizzle sets rain the instant Pelipper enters — no move required. Its base 65 Speed is intentionally low; the standard turn 1 is Protect while a teammate disrupts, then set Tailwind or fire Hurricane, which is 100% accurate in rain. Damp Rock extends rain to 8 turns if longevity is prioritized over survivability.
Basculegion
Water / Ghost · Adaptability
Basculegion's meta build runs Adaptability (approximately 93% usage) rather than Swift Swim (6.8%). Last Respects gains 50 base power per fainted ally; Adaptability's 2× STAB multiplier stacks multiplicatively for enormous late-game damage independent of rain. Its Ghost typing grants immunity to Fake Out — critical for negating the most common lead disruption in the format.
Slots 4–6: The Support Shell
In bring-6-pick-4, your final three slots are a matchup toolbox. These are the most consistent support options and what each one contributes.
Archaludon
Steel / Dragon · Stamina · Electro Shot Core
Under rain, Electro Shot fires immediately without a charge turn and raises Special Attack by one stage on every use — the snowball effect is rapid. Steel/Dragon typing provides a full resistance to Grass moves, directly patching the core's primary weakness. Note: coordinate with Pelipper (a Flying-type) when Mega Swampert uses Earthquake to avoid friendly fire. Archaludon appears alongside Mega Swampert and Pelipper in 82.7% of recorded teams.
Incineroar
Fire / Dark · Intimidate · Universal Support
Fake Out disrupts the biggest turn 1 threat for free, Intimidate lowers opposing physical attackers, and Parting Shot safely cycles Pelipper back in to reset rain if it was forced out. Rain reduces its Fire moves by 50%, but Flare Blitz still threatens specific Grass-type targets. Incineroar is the most important tool for keeping Pelipper alive longer and making rain leads safer.
Grimmsnarl
Dark / Fairy · Prankster · Speed & Screen Control
Prankster gives Light Screen and Reflect priority activation, building a defensive buffer before Mega Swampert needs to sweep. Particularly effective against special attack-heavy leads. Parting Shot adds a second source of Special Attack debuffing alongside Incineroar, giving the team two pivoting supporters and extra insurance against special-oriented threats.
How to Pilot Rain: Turn-by-Turn Strategy
Incineroar + Pelipper
Turn 1: Incineroar uses Fake Out on the biggest threat; Pelipper uses Protect. Drizzle activates on entry — rain is already set.
Turn 2: Incineroar uses Parting Shot to bring in Mega Swampert while debuffing. Pelipper sets Tailwind or fires Hurricane. Mega Swampert enters, triggers Mega Evolution, gains Swift Swim.
Turn 3+: Mega Swampert sweeps at approximately 220 Speed under Swift Swim. Earthquake chips both targets; Wave Crash for high single-target damage; Ice Punch for Grass-type cleanup.
Basculegion + Pelipper
Against Incineroar + Torkoal sun leads, Basculegion's Ghost typing makes it Fake Out immune — the opponent cannot use their standard disruption opener. Pelipper overrides Drought immediately; Basculegion threatens Wave Crash or Aqua Jet under rain, forcing the opponent to choose between protecting Torkoal or answering the offensive pressure.
Mega Evolve as Early as Possible — After Rain is Up
Swampert before Mega Evolving runs Torrent or Damp — no speed bonus in rain. The correct sequence: confirm Pelipper has set rain, then bring Swampert in and Mega Evolve immediately for Swift Swim. If Pelipper is knocked out before rain ends, Mega Swampert loses the speed advantage (drops to approximately 110 Speed) but retains base 150 Attack for continued physical output — shift to a raw damage play style rather than relying on Speed priority.
Weaknesses & How to Address Them
Electric Weakness
Rain makes Thunder 100% accurate. Mega Swampert (Ground type) is immune to Electric, but Pelipper is not. Archaludon ironically becomes a threat mirror — opponents using Electro Shot freely under your own rain is a genuine risk if Archaludon is on the opposing team.
Keep Mega Swampert healthy as the Electric counter — it absorbs all Electric moves. Wide Guard from Pelipper blocks spread Discharges. Archaludon's Steel typing resists Electric moves if it's on your side.
Grass Weakness
Grass moves hit Water-types for 2× damage. Sinistcha and Amoonguss are specifically brought to trouble rain teams — their Grass moves threaten the entire Water-type core, and their bulk means they often survive a hit before getting removed.
Mega Swampert's Ice Punch directly threatens most Grass-types. Archaludon's Electro Shot hits Grass-types for 2× and fires instantly under rain with a Special Attack boost — the cleanest answer to both Sinistcha and Amoonguss in a single slot.
Weather Override
Mega Charizard Y (Drought) and Tyranitar (Sand Stream) override rain on entry, stripping Swift Swim speed advantages instantly. Weather wars are the most heavily prepared-against matchup in Regulation M-B, and every rain team needs a clear plan for the weather reset scenario.
Re-entering Pelipper immediately restores rain. Basculegion's Last Respects and Aqua Jet function independent of weather — output does not fully stop. Parting Shot rotation keeps Pelipper healthy enough to re-enter and re-set rain; mastering this cycle is the key technical skill for high-level rain play.
Trick Room Reversal
Trick Room completely inverts the speed advantage — Mega Swampert at 220 Speed moves last under Trick Room. This turns rain's greatest strength into an instant liability. Identifying TR setters in Team Preview is critical; having no answer in your bring-6 is often a direct loss.
Grimmsnarl's Prankster Parting Shot or Incineroar's Fake Out buys a turn to prevent TR setup. Pelipper's Hurricane (100% accurate in rain) can OHKO common low-Speed TR setters before they move. Basculegion's Aqua Jet has priority and therefore still moves first even under Trick Room's reversal.
Usage Rate & Meta Data
Source: Pikalytics Pokémon Champions Regulation M-B S3 Ranked Battle Data, 11,000+ recorded battles. Pelipper maintains 100% Drizzle ability usage, confirming it as the only weather-setter in the archetype. Archaludon reaches 13.8% usage and 52.4% win rate in ranked, confirming its status as the critical fourth slot in top-tier rain compositions.
Key Damage Calculations
Hits both opposing Pokémon for cumulative pressure. After a Fake Out safety turn, two Earthquakes secure the KO with any prior chip damage across the field.
Rain and Adaptability multiply together for extreme effective power. Even against a physically defensive spread, 70%+ in one hit means any chip secures the KO. Note: Wave Crash deals recoil damage — manage Basculegion HP in extended games.
Hurricane at 100% accuracy in rain removes all reliability concerns from its base 70% hit rate. The 2× effectiveness against Grass types like Amoonguss gives near-or-guaranteed OHKO damage — Pelipper can remove its own primary Grass-type counter without needing to rely on Archaludon, keeping the latter free for other targets.
※ All figures are L50 approximations. Actual values vary based on SP training distribution, IVs, and target builds.
Sharpen Your Rain Team with PokeStats Tools
Calculate Mega Swampert's Swift Swim speed tiers and rain damage output to fine-tune your SP training builds.