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Pokemon X and Y Phase 10: Mewtwo (Unknown Dungeon)

The OG legendary — Mewtwo lives in a hidden chamber at the back of Pokemon Village called the Unknown Dungeon .

Nintendo 3DS Pokemon X / Pokemon Y Pokemon X and Y trainer artwork of Professor Sycamore. Phase 10 Post-Game Professor Sycamore Kalos Professor Looker Bureau, Kiloude, Mewtwo, Zygarde, and Mega Stones. 10 / 10 Zygarde artwork
By Damodar Sharma Updated May 25, 2026 Walkthrough

Phase 10 section 6 of 15

The OG legendary — Mewtwo lives in a hidden chamber at the back of Pokemon Village called the Unknown Dungeon .

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Mewtwo (Unknown Dungeon)

The OG legendary — Mewtwo lives in a hidden chamber at the back of Pokémon Village called the Unknown Dungeon. Lv 70. The cave entrance was blocked during Phase 8; it opens after Hall of Fame.

Mewtwo

Mewtwo

Psychic · Lv 70 · Ability: Pressure / Unnerve (HA)

Moves: Psychic, Aura Sphere, Barrier, Recover.

Drops: ★ ★ ★ Mewtwonite X (Pokémon X) or Mewtwonite Y (Pokémon Y) when caught — different Mega per version. Mega Mewtwo X is Psychic/Fighting (Steadfast). Mega Mewtwo Y is pure Psychic (Insomnia, massive Sp.Atk).

How to find it: Fly to Snowbelle, head to Route 20 (Winding Woods), through to Pokémon Village. At the back of the village, the previously-blocked cave is now open — enter the Unknown Dungeon. Mewtwo is in the central chamber.

★ ★ ★ Catch strategy:
  1. Save before the chamber.
  2. Lead with a False Swipe user (Pangoro, Bisharp, Gallade). Recover means Mewtwo can heal back — be patient.
  3. Status: Thunder Wave (Klefki Prankster) or Sleep Powder (Vileplume/Amoonguss) — paralysis/sleep boost catch rate.
  4. Watch Barrier — boosts Defense by 2 stages. Doesn't affect your special hits but matters for False Swipe.
  5. Start throwing Ultra Balls / Dusk Balls (the cave is dark — Dusk Ball gets 3.5× multiplier).
  6. Timer Balls become more effective after 20+ turns.
  7. If you have Master Ball still: 100% guaranteed catch.

Version Note — Mewtwonite

X exclusiveMewtwonite X — Mega Mewtwo X is Psychic/Fighting, Steadfast ability, max Attack +30 / Sp.Atk +40 / Speed +10. Mixed sweeper.
Y exclusiveMewtwonite Y — Mega Mewtwo Y is pure Psychic, Insomnia ability, Sp.Atk +66. Special glass cannon.
RecommendationBoth are top-tier. Mega Mewtwo Y is the strongest pure-power option. Mega Mewtwo X is more versatile. Trade across versions to collect both Mega Stones.

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