GBL Note
← GBL NoteIV rank checkerShadow Rhyperior
Shadow Rhyperior

Shadow Rhyperior IVs — Attack 15 Required (Mirror CMP) · Master League

💯 CP 4221 · L50 · Season 28 (2026.09.08~12.01) · Updated 2026-10-09

Got a Shadow Rhyperior you've been scraping XL for, and it didn't come out 100%? Before you power up — 30 seconds. We simulated the entire Master top 100 to see whether that spread is fine to build.

For Shadow Rhyperior, attack 15 is effectively mandatory, and the IVs are tight, so a high catch is safest. Below is the result of running the Master top 100 through a battle simulator, plus the mirror and best buddy. (Hundo 1-shield record: 45W 55L.)

Compromise IVs
15/15/15
IV-tight — an effective hundo is safest. See the verdict below.

Build it or not — at a glance

✅
Just build · 15/15/15 (effective hundo)
This Pokémon is IV-tight — aim for an effective hundo (or very close).
⚠️
Conditional · around 15/15/14
You start dropping Xerneas and similar. If you rarely face them (low real pick rate), it's fine to run.
❌
Don't build yet · Attack 14 or below
Shadow Rhyperior always loses CMP priority to the mirror at attack 14. Don't build it — wait for a better one.

🔬 Full-meta sim — all 100, who you meet & beat

1-on-1 battles vs the Master League top 100, per shield. Green = win, red = loss. (Rating 500 = even; higher = more comfortable.)

45W45%55L
Palkia (Origin)213
Zacian (Crowned Sword)647
Zygarde (Complete Forme)272
Metagross421
Kyurem (White)486
Reshiram773
Xerneas239
Kyogre152
Dialga (Origin)773
Eternatus522
Ursaluna230
Kyurem (Black)454
Reshiram (Shadow)739
Lugia435
Lunala515
Zamazenta (Crowned Shield)647
Ursaluna (Shadow)279
Necrozma (Dawn Wings)565
Marshadow247
Zekrom773
Zekrom (Shadow)739
Necrozma (Dusk Mane)609
Lugia (Shadow)469
Palkia (Shadow)248
Ho-Oh829
Garchomp (Shadow)302
Metagross (Shadow)491
Groudon432
Melmetal665
Keldeo (Resolute)210
Garchomp246
Gyarados (Shadow)110
Kyogre (Shadow)192
Palkia213
Latios (Shadow)287
Keldeo (Ordinary)210
Rillaboom161
Yveltal187
Giratina (Altered) (Shadow)565
Florges485
Landorus (Therian)184
Solgaleo708
Dialga (Shadow)739
Meloetta (Aria)538
Primarina229
Dialga773
Gholdengo589
Kyurem268
Latios247
Dragonite (Shadow)114
Mewtwo (Shadow)312
Giratina (Altered)582
Groudon (Shadow)672
Hydreigon (Shadow)544
Goodra239
Ho-Oh (Shadow)795
Latias (Shadow)267
Gyarados110
Togekiss589
Tapu Lele744
Jirachi769
Latias447
Enamorus (Therian)607
Tyranitar (Shadow)600
Mewtwo544
Conkeldurr (Shadow)322
Dragonite95
Rhyperior (Shadow)500
Rhyperior500
Sylveon674
Heatran (Shadow)874
Genesect (Shock)291
Genesect (Chill)291
Raikou (Shadow)594
Baxcalibur295
Salamence (Shadow)562
Urshifu (Single Strike)728
Darkrai (Shadow)385
Kingambit580
Snorlax (Shadow)713
Hydreigon600
Volcanion444
Golisopod (Shadow)195
Urshifu (Rapid Strike)211
Tyranitar632
Heatran876
Raikou663
Golisopod152
Zapdos818
Zapdos (Shadow)764
Hippowdon (Shadow)265
Snorlax484
Annihilape465
Mamoswine (Shadow)327
Annihilape (Shadow)318
Zacian (Hero)872
Zamazenta (Hero)526
Genesect (Burn)291
Landorus (Incarnate)116
Kommo-o544
⭐ Best Buddy (L51) effect — newly won matchups
Opponents you newly beat once best-buddied. The result depends on whether the opponent is best-buddied too, so both cases are shown.
Opp not BB (L50) · +3W
Kyurem⭐
Rhyperior (Shadow)⭐
Rhyperior⭐
Opp also BB (L51) · +0W
none
※ The mirror and same-stat rival return to a tie when the opponent is best-buddied too (both L51). So Best Buddy only wins the mirror when the opponent isn't best-buddied.

Why attack 15 is mandatory — CMP

Attack decides priority. Attack 14 always loses to a same-stat rival.

vsMirror (Shadow Rhyperior vs Shadow Rhyperior)
Mine (atk 14) vs Foe (atk 15)
shields0
L
224
shields1
L
450
shields2
Tie
500

Verdict by IV spread (Master League sim)

💡 15/15/15 at the top is the perfect IV (best); rows go to lower IVs downward.
Perfect·Battle-equal= win/loss identical to a hundo (no disadvantage — just use it).
Fine= it only loses to weaker (non-top) opponents, so it's acceptable to run.
N lost= it starts losing to N strong top-10 opponents — a real disadvantage.
CMP loss= at attack 14 you always lose the mirror / same-stat rivals.
‘Matchups lost’ = opponents you newly lose to at that spread (0/1/2 shields = how many shields are used).
IVs (Atk/Def/Sta)CPHPVerdictMatchups lost
15 / 15 / 154221223Perfectnone
14 / 15 / 154204223CMP lossnone
15 / 15 / 1442132221 lost
XerneasXerneas·shields0
15 / 15 / 1342052211 lost
XerneasXerneas·shields0
15 / 15 / 1241972201 lost
XerneasXerneas·shields0
15 / 14 / 1542102231 lost
XerneasXerneas·shields0
15 / 14 / 1442022221 lost
XerneasXerneas·shields0
15 / 14 / 1341942211 lost
XerneasXerneas·shields0
15 / 13 / 1441922221 lost
XerneasXerneas·shields0
15 / 13 / 1341842211 lost
XerneasXerneas·shields0
15 / 12 / 1441822221 lost
XerneasXerneas·shields0
15 / 10 / 1441612223 lost
XerneasXerneas·shields0Lugia (Shadow)Lugia (Shadow)·shields0RhyperiorRhyperior·shields2

Why attack 15 matters — CMP

Master League has no CP cap, so everyone is max level. When same-species (mirror) or same-stat Pokémon fire a charged move on the same turn, the higher effective attack goes first (CMP). An attack-14 Shadow Rhyperior loses that priority to an attack-15 opponent. In the sim, the attack-14 mirror came out 0-shield=loss, 1-shield=loss, 2-shield=tie. In a mirror-heavy meta, attack 15 is effectively mandatory.

Where win/loss starts to split

Shadow Rhyperior is IV-tight. Even dropping to 15/15/14 starts losing Xerneas. Across the full top-100 sim, small stat cuts cross breakpoints and flip matchups, so a high-IV catch is the safer play here.

Best Buddy — depends on whether the opponent is too

Best Buddy (level +1) depends on whether the opponent is best-buddied. Against a non-best-buddied opponent (L50) you newly win 3 matchups at 1 shield; against a best-buddied one (L51), 0. Top Master legendaries are usually best-buddied, so the mirror and same-stat rivals go back to a tie when both are L51. It never hurts, but it doesn't magically win the mirror.

Note that this line moves with the meta. If usage shifts or a new Pokémon arrives, the breakpoints move and a spread that's fine today can get shaky. This analysis is for Season 28 (2026.09.08~12.01); when the season changes we re-run the full top-100 sim and update it.

⭐Best Buddy (L51) effectBB CP 4271 · L51

Best-buddying even a compromise improves every matchup and beats same-stat rivals.

Hundo record by shield count

shields 0
52W · 48L
shields 1
45W · 55L
shields 2
40W · 60L

Bottom line — attack 15 is non-negotiable (mirror CMP), IV-tight, aim high. Based on the Season 28 (2026.09.08~12.01) meta; updated when the season changes.

FAQ

Q. Do I need a hundo Shadow Rhyperior?
Shadow Rhyperior is IV-tight, so an effective hundo (or very close) is safest. From 15/15/14 you start losing Xerneas. That said, if those losses are low-pick-rate, the real impact may be small.
Q. Attack is 14 — can I just build it?
Not recommended. At attack 14 you lose CMP priority to the mirror and same-stat rivals — a fight that should be 50:50 becomes 0:100.
Q. How long does this hold?
It's the Season 28 (2026.09.08~12.01) meta. When the meta shifts, the breakpoints and the compromise line move, so we re-run the full top-100 sim each season and update it.
Method
BasisSeason 28 (2026.09.08~12.01)ScopeMaster League Top 100Shields0 · 1 · 2Level50 / Best Buddy 51Battle engineGBL Note Simulator (PvPoke-based)Baseline15/15/15Last calculated2026-10-09
✔ Calculated & analyzed by GBL Note

These verdicts come from simulating each spread against the entire Master League top-100 across 0/1/2-shield scenarios with the open-source PvPoke engine. If no matchup flips versus a hundo it's 'Perfect/Battle-equal'; if it only loses to weaker (non-top) opponents it's 'Fine'; once it loses to a top-10 opponent it's 'N lost' by the number of losses. Attack 14 loses mirror priority — 'CMP loss'.

About the method →
Tier listSimulatorPrivacy
Shadow Rhyperior IVs — Attack 15 Required (Mirror CMP) · Master League | GBL Note