Pokemon FireRed and LeafGreen
Pokemon FireRed and LeafGreen

Post-Game: Mewtwo & Cerulean Cave

Conquer Mewtwo in Pokemon FireRed and LeafGreen's post-game. This guide covers entry requirements for Cerulean Cave and defeating the Psychic-type legend.

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Post-Game: Mewtwo & Cerulean Cave

Congratulations, Trainer! Defeating the Elite Four and becoming the Champion of Kanto was a monumental achievement. However, your journey is far from over. A legendary challenge awaits in the depths of Cerulean Cave, home to the formidable Psychic-type Pokémon, Mewtwo.

Prerequisites for Entry

Before you can even set foot in Cerulean Cave, there are a few crucial steps you must complete:

  • Become the Champion: You must have successfully defeated the Elite Four and your rival, becoming the reigning Pokémon League Champion.
  • Complete the Sevii Islands Quest: This involves a series of tasks across the Sevii Islands. Specifically, you need to have:

    • Obtained the Ruby on Island One and given it to Celio.
    • Obtained the Sapphire from Island Six (Dotted Hole) and Island Five (Rocket Warehouse) and given it to Celio. This will enable trade functionality with Pokémon Ruby, Sapphire, and Emerald.

Once these conditions are met, the guard blocking the entrance to Cerulean Cave will finally step aside, allowing you access.

Preparing for Mewtwo

Mewtwo is a Level 70 Psychic-type Pokémon with incredibly high Special Attack and Speed. It's one of the toughest battles in the game, so preparation is key. Here's what you'll need:

Your Battle Team:
  • High-Level Pokémon: Aim for Pokémon around Level 65-70 or higher. Mewtwo's power is immense.
  • Type Advantage: Dark-type and Bug-type Pokémon are your best bet against Psychic-types. However, strong Ghost-type attacks can also be effective. Consider Pokémon like:
    • Snorlax: While not having a type advantage, Snorlax's high HP and Special Defense make it a great tank. Teach it Shadow Ball via TM30.
    • Jolteon/Zapdos: Fast Electric-types can outspeed Mewtwo and deal significant damage, especially if you can land a critical hit.
    • Alakazam/Gengar: If you have a strong Psychic or Ghost-type of your own, they can be valuable, but be wary of Mewtwo's powerful Psychic attacks.
  • Status Inducers: Pokémon that can inflict Sleep (e.g., Hypnosis, Spore) or Paralysis (e.g., Thunder Wave) are invaluable for making Mewtwo easier to catch.
  • False Swipe User (Optional but Recommended): A Pokémon with the move False Swipe (e.g., Scyther, Parasect) can reduce Mewtwo's HP to 1 without knocking it out, significantly increasing your chances of capture.
Essential Items:
  • Ultra Balls: Stock up on at least 30-50 Ultra Balls. You'll need them.
  • Timer Balls: These become more effective the longer the battle lasts, making them excellent for a drawn-out legendary encounter.
  • Master Ball (If you still have it): If you haven't used your Master Ball yet, this is its ultimate purpose. It guarantees a capture.
  • Full Restores/Max Potions: Keep your Pokémon healthy.
  • Full Heals/Lava Cookies: To cure any status conditions Mewtwo might inflict.
  • Elixirs/Max Elixirs: To restore PP for your key moves.

Navigating Cerulean Cave

Cerulean Cave is a maze, and wild Pokémon here are incredibly strong (Levels 46-70). Be prepared for frequent encounters with Pokémon like Golbat, Parasect, Electrode, and Ditto. You'll need:

  • Surf: To cross water bodies.
  • Strength: To move boulders.
  • Rock Smash (Optional): For breaking certain rocks, though not strictly necessary for progression to Mewtwo.
Walkthrough:
  1. Entrance: From Cerulean City, head north across Nugget Bridge and then west, Surfing across the water. The cave entrance is on the small island.
  2. First Floor (1F):
    • Upon entering, head north and then west. You'll need to Surf across a small body of water.
    • Continue west and then south, navigating around the rock formations.
    • You'll find a ladder leading down to the B1F.
  3. Basement 1 (B1F):
    • From the ladder, head south and then west. You'll encounter a large body of water.
    • Surf across this water, heading generally west.
    • On the western side, you'll find a small landmass with a ladder leading up to the 1F.
  4. Back on First Floor (1F - Second Section):
    • You'll emerge in a different section of the 1F. Head north.
    • You'll see a large, open area. Mewtwo is located on a small island in the center of this area.
    • Surf across the water to reach Mewtwo.

The Mewtwo Encounter

Once you interact with Mewtwo, the battle will begin immediately. Remember these strategies:

  • Save Before Engaging: This is paramount! Save your game right in front of Mewtwo. If you accidentally knock it out or run out of Poké Balls, you can simply reset your game and try again.
  • Inflict Status: Your first priority should be to inflict a status condition like Sleep or Paralysis. Sleep offers a higher catch rate, but Paralysis is permanent.
  • Lower HP: Once a status is applied, use your strongest attacks to bring Mewtwo's HP down into the red. If you have a False Swipe user, this is where it shines.
  • Throw Balls: Once Mewtwo is at low HP and under a status condition, start throwing your Ultra Balls and Timer Balls. Be patient; it might take many attempts.
  • Heal and Reapply: Mewtwo will hit hard. Be ready to use Full Restores on your Pokémon. If its status wears off, reapply it as soon as possible.
  • Master Ball (Last Resort/Easy Capture): If you're struggling and still have your Master Ball, now is the time to use it for an instant capture.

Capturing Mewtwo is a true test of your Trainer skills. Good luck, and enjoy your new, incredibly powerful legendary Pokémon!