20. Charizard-Mega-Y

Fire/Flying · Drought · VR A- · 8.25% (2026-04) · base 78 / 104 / 78 / 159 / 115 / 100 · the format’s premier auto-sun special wallbreaker — Drought turns a 159-SpA Weather Ball into a Fire nuke and erases Solar Beam’s charge turn the moment it Megas in.

Format role

Charizard-Mega-Y is the reason “sun offense” exists as an archetype. Mega Evolving sets Drought unconditionally, granting a 1.5x boost to its Fire STAB and — the load-bearing part — converting Weather Ball into a 100-BP Fire move (it doubles in weather and becomes Fire-typed) while making Solar Beam fire chargeless. As a turn-one lead it forces the opponent to commit a Fire-resist or a dedicated special wall on the spot. It eats your single Mega slot, so you build around the sun, not splash it. Its crippling 4x Stealth Rock weakness is fixed, so it is acutely hazard-fragile — keep your own side of the field clean when you bring it. It is a wallbreaker, not a sweeper: base 100 Speed (Timid 328) sweeps nothing unboosted; its job is to punch the holes a faster offense exploits.

Sets

The block is monotype on ability and item: Drought 100%, Charizardite Y 100%. Spreads are max-SpA/max-Spe; the split is Timid 0/0/0/252/4/252 (53.3%) vs Modest 0/0/4/252/0/252 (16.3%) plus minor variants (Timid 4-Def 13.4%, Modest 252/4 SpD 4.3%, Timid bulk-leaning 4.0%). The only real build choice is nature (speed vs power) and which three coverage/utility moves accompany the Weather Ball + Solar Beam core.

Sun Nuke (standard — Timid is the 53% line)

Charizard-Mega-Y @ Charizardite Y
Ability: Drought  |  Nature: Timid
EVs: 0 HP / 0 Atk / 0 Def / 252 SpA / 4 SpD / 252 Spe
- Solar Beam        (96.6%)
- Weather Ball      (84.1%)
- Scorching Sands   (72.4%)  / Focus Blast (23.1%)
- Roost             (38.8%)  / Overheat (29.6%)

Solar Beam (96.6%) and Weather Ball (84.1%) are the near-mandatory core — Weather Ball is the primary Fire STAB here, not Fire Blast (only 12.1%), because in sun it is a 100% accurate 100-BP nuke with no Choice/PP downside. Scorching Sands (72.4%) is the most common third slot: chip + burn on the Heatran/Tyranitar/opposing-Fire that resist its STAB. The last slot picks from Roost (38.8%, longevity to recycle the breaker), Overheat (29.6%, the one-time bigger nuke for a specific key KO), Focus Blast (23.1%, the only move that dents Blissey/Chansey/Tyranitar), or Ancient Power (19.2%, an anti-Fire/Flying lure). You realistically run three of {Scorching Sands, Roost, Overheat, Focus Blast}.

Modest variant (~21% combined) — same template, Timid→Modest. Trades the 328-Speed jump-point (you drop to base-100 neutral, 299, and lose the mirror) for a damage tier that flips key rolls — e.g. Weather Ball turns 252 HP Landorus-Therian from a Timid 2HKO / OHKO roll into a much stronger OHKO roll. Run Modest only when your team carries its own answer to opposing sun/scarfers.

Legality note: the item slot is locked to Charizardite Y, so Zard-Y can never hold a Heat Rock — its own Drought lasts the base 5 turns. Eight-turn sun must come from a separate Drought + Heat Rock holder (Torkoal/Ninetales), a different teamslot entirely.

What it does

Lead, Mega, set Drought, and immediately threaten a 2HKO across most of the board with Weather Ball while Solar Beam — chargeless in sun — pre-empts the bulky Waters and Grounds that would otherwise wall the Fire STAB. The sequencing is brutal: the turn the opponent brings their Fire-resist (Water/Rock/Dragon), Solar Beam already answers it at full speed. Key interactions for an offense player:

• Weather Ball IS the STAB. Out of sun it’s a 50-BP Normal move — Zard-Y is dead weight if the weather flips. Keeping sun up is the entire game plan; losing it (to sand/rain) turns the nuke into nothing.
• Solar Beam is a permanent coverage move, not a liability. No charge in sun means it’s a same-turn answer to Toxapex-class Waters and to the Rock checks (it can OHKO Diancie-Mega on the switch — high roll only, see calcs).
• Scorching Sands beats the Fire-immune. Flash Fire Heatran is immune to both STABs; Sands is the only common move that hits it (2HKO + burn chance on defensive Tran), making it the dedicated anti-Heatran/anti-opposing-Fire tech.
• Roost is the longevity lever. A breaker that pivots in twice and Roosts off chip threatens the same hole all game; against fat that out-values a fourth attack.
• Hazard-fragile to the point of mandate. Stealth Rock = 50% on entry (4x weak). One SR layer caps Zard-Y at roughly two switch-ins. Spinning your own rocks off and getting rocks up on the opposing sun lead are both first-priority.
• Drought is a double-edged weather war. It cancels opposing rain/sand and halves enemy Water moves, but Tyranitar/Hippowdon sand and Pelipper rain directly overwrite it and neuter the whole plan.

Load-bearing calcs

Timid 252 SpA (417) unless noted; “WB sun” = Weather Ball as a 100-BP Fire move with sun’s ×1.5.

Takeaways: Weather Ball heavily pressures the neutral board — Lando-T, Great Tusk — often OHKOing offensive spreads and 2HKOing bulkier ones, and against the super-effective Steel/Ghost Gholdengo it cleanly OHKOes from full even through full SpD investment; Overheat does the same with room to spare. But its listed checks are real: Diancie-Mega survives Weather Ball and forces the Solar Beam read, Multiscale Dragonite and Mega-Latios shrug off the resisted STAB, and specially-invested Toxapex walls both STABs. The breaker’s ceiling is enormous; its checks are specific and predictable.

Checks & counters

HARD counters / top switch-ins (from the block’s Checks & Counters):

• Diancie-Mega (70.1) — the #1 answer. Rock/Fairy resists Weather Ball (it does ~47%), Magic Bounce reflects conventional status hazards, and it threatens back with Earth Power / Moonblast. Its only fear is a hard-read Solar Beam (which OHKOs on the switch), so it’s a check that can be punished, not a free wall.
• Latios-Mega (59.5) — Levitate Dragon/Psychic resists the Fire STAB, outspeeds (base 110), and revenge-kills with its own special game. Switched out 72% of the time it comes in — it answers but rarely sits.
• Dragonite (59.5) — Multiscale + Dragon-resist means Weather Ball does ~25% through the screen; it sets up Dragon Dance on you or Extreme-Speeds the chipped Zard-Y.
• Charizard-Mega-X (58.8) — the disguise mirror: Fire/Dragon resists Weather Ball to 0.25x, shrugs it off, and DDs up in your face (note: only one team can run a Mega, so this is an opposing-team check, not a teammate option).

SOFT checks / revenge:

• Zamazenta (51.4) — takes a neutral Weather Ball but the 412-Speed wall (max+ base 138) vastly outpaces 328 and revenges with Crunch / pivots out.
• Flash Fire Heatran — full Fire immunity to both STABs; only Scorching Sands hits it, and that 2HKOes specially-defensive variants only with the burn + a second hit, so it pivots out rather than absorbing freely.
• Specially-defensive Toxapex — walls both STABs (Solar Beam ~28–33% — Grass is neutral into Poison/Water, but it’s still only a 3–4HKO into Regenerator — and Weather Ball resisted), Regenerates, burns/Toxics back.
• Stealth Rock itself — a “check” that caps Zard-Y at ~two entries; the cheapest answer in the format.
• Any Scarf base-100+ that resists or outspeeds 328 revenges a chipped Zard-Y.

★ Offense angle

Zard-Y is the offensive build’s opening hole-puncher, not the wincon — slot it as the lead that forces a defensive commitment, then cash the chip with faster threats.

1. Lead, Mega, set sun, fire Weather Ball. Against most leads you immediately threaten 90%+ (OHKO on Great Tusk/Gholdengo offensive spreads) and the opponent must take it or sack the matchup. The forced early switch is the read you punish.
2. Pair it with hazards that grind its own checks. Diancie-M/Heatran/Toxapex are passive — they come in, you may not kill, but Stealth Rock + a Knock Off partner wears them down across the breaker’s repeat trips. Roost-Zard-Y plus chip is the win condition vs fat.
3. Weaponize the sun beyond Zard-Y. Drought is team-wide: it powers a Sun-boosted secondary Fire attacker, enables off-team Chlorophyll sweepers, and halves incoming Water moves (×0.5), opening your physical attackers against bulky Waters. Build so the sun matters on turns Zard-Y is off the field.
4. Mirror / opposing-sun math. Timid 328 wins the speed tie vs Modest (299) sun leads and ties other base-100s — at this jump-point you fire first. Drop to Modest only if your team brings Scarf insurance, because Modest turns 252 HP Lando-T in sun into a much stronger OHKO roll (vs a Timid 2HKO / OHKO roll).
5. Respect the weather war. Do not lead into a known Tyranitar/Hippowdon/Pelipper team without a plan to keep sun up — losing the weather turns your nuke into a 50-BP Normal Weather Ball.

The clean read: Zard-Y softens, your Booster/Scarf/priority finishes. Its Weather Ball + Overheat remove the Steel walls (Gholdengo OHKO) that brick a Kingambit Sucker sweep, and its Solar Beam clears the bulky Waters that wall a fast Water/Electric cleaner.

Top teammates & cores

From the block’s top-10: Raging Bolt 44.1%, Great Tusk 37.8%, Iron Valiant 23.2%, Chansey 23.1%, Gliscor 22.2%, Alomomola 20.5%, Toxapex 18.8%, Clefable 18.2%, Kingambit 17.9%, Iron Treads 15.9%.

The two load-bearing cores:

• Zard-Y + Raging Bolt (44.1%) — the headline pairing. A double special-breaker core with near-orthogonal pressure: bulky Grounds that block Bolt’s Electric STAB hate Zard-Y’s sun Weather Ball / Solar Beam pressure, while Fire/Rock/Dragon answers that try to stomach Zard-Y (Diancie-Mega, opposing Zard-X, Dragonite/Latios-style pivots) dislike Bolt’s Electric/Dragon coverage or Thunderclap revenge pressure. Bolt also revenges the fast scarfers that would otherwise pick off a chipped Zard-Y. This is the most common — and most cohesive — Zard-Y core in the format.
• Zard-Y + Great Tusk (37.8%) — the support backbone. Tusk Rapid Spins to keep Stealth Rock off the 4x-weak Zard-Y (the single most valuable support it can get), Knocks Off the items of the passive Diancie-M/Toxapex/Heatran checks, sets your own SR, and its Ground STAB pressures the Heatran/Tyranitar that wall the sun. This is the hazard-control spine of sun offense.

Iron Valiant (23.2%) adds a fast mixed revenge breaker that punishes the same frail offense Zard-Y softens, and Gliscor/Iron Treads round out the hazard + spin shell that a Stealth-Rock-allergic breaker demands.