Got a Xerneas 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 Xerneas, 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: 72W 28L.)
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 Raikou (Shadow) and similar. If you rarely face them (low real pick rate), it's fine to run.
❌
Don't build yet · Attack 14 or below
Xerneas 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.)
72W72%28L
329
726
311
894
431
500
575
614
419
913
347
641
632
579
652
700
586
375
522
627
275
591
694
239
694
412
728
557
511
432
333
573
550
376
289
609
284
393
705
547
595
894
796
293
573
611
639
737
593
769
331
723
673
705
614
618
494
682
698
748
291
104
735
819
716
465
591
486
682
700
609
419
760
577
751
664
662
735
655
404
570
365
639
714
430
609
837
474
589
673
682
767
632
607
675
611
831
639
543
696
⭐ 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) · +1W
⭐
Opp also BB (L51) · +1W
⭐
※ 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 (Xerneas vs Xerneas)
Mine (atk 14) vs Foe (atk 15)
shields0
패
445
shields1
무
500
shields2
패
394
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).
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 Xerneas loses that priority to an attack-15 opponent. In the sim, the attack-14 mirror came out 0-shield=loss, 1-shield=tie, 2-shield=loss. In a mirror-heavy meta, attack 15 is effectively mandatory.
Where win/loss starts to split
Xerneas is IV-tight. Even dropping to 15/15/14 starts losing Raikou (Shadow). 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 1 matchups at 1 shield; against a best-buddied one (L51), 1. 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 27 (2026.06.02~09.09); when the season changes we re-run the full top-100 sim and update it.
⭐Best Buddy (L51) effectBB CP 4326 · L51
Best-buddying even a compromise improves every matchup and beats same-stat rivals.
Hundo record by shield count
shields 0
73W · 27L
shields 1
72W · 28L
shields 2
61W · 39L
Bottom line — attack 15 is non-negotiable (mirror CMP), IV-tight, aim high. Based on the Season 27 (2026.06.02~09.09) meta; updated when the season changes.
FAQ
Q. Do I need a hundo Xerneas?
Xerneas is IV-tight, so an effective hundo (or very close) is safest. From 15/15/14 you start losing Raikou (Shadow). 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 27 (2026.06.02~09.09) 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 27 (2026.06.02~09.09)ScopeMaster League Top 100Shields0 · 1 · 2Level50 / Best Buddy 51Battle engineGBL Note Simulator (PvPoke-based)Baseline15/15/15Last calculated2026-09-01
✔ 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'.
