Phase 10
Pokemon FireRed and LeafGreen Phase 10: Post-Game Sevii Islands Walkthrough
Phase 10 of the Pokemon FireRed and LeafGreen walkthrough: National Dex, One-Seven Islands, Rocket Warehouse, Tanoby, Trainer Tower, Altering Cave, and Mewtwo.
National Dex, One-Seven Islands, Rocket Warehouse, Tanoby, Trainer Tower, Altering Cave, and Mewtwo. Open each section page for source-backed encounter tables, trainer teams, hidden item rows, and boss cards.
Phase 10
National Dex, One-Seven Islands, Rocket Warehouse, Tanoby, Trainer Tower, Altering Cave, and Mewtwo.
FR/LG reminder
Use version rows for exclusives and remember that the remakes add abilities, natures, held items, the VS Seeker, Sevii Islands, and National Dex post-game routing.
Section Pages
After the Hall of Fame, obtain the National Dex if you have enough owned Pokemon, return to Celio, receive the Rainbow Pass, and retrieve the Ruby from Mt. Ember's Rocket path.
Phase 10Four Island and Icefall CaveVisit Four Island, use Waterfall in Icefall Cave, help Lorelei against Team Rocket, and collect cave rewards.
Phase 10Five Island, Resort Gorgeous, Lost Cave, Memorial Pillar, and Rocket WarehouseExplore Five Island's branches, solve Lost Cave navigation, clear Memorial Pillar, and raid Rocket Warehouse for the Sapphire.
Phase 10Six Island, Pattern Bush, Outcast Island, Ruin Valley, and Dotted HoleExplore Six Island, clear Pattern Bush and Outcast Island, use Cut at Dotted Hole, witness the Sapphire theft, and gain the second Rocket Warehouse password.
Phase 10Seven Island, Sevault Canyon, Tanoby Key, Tanoby Ruins, Trainer Tower, and Altering CaveComplete the long Seven Island routes, solve Tanoby Key, unlock Tanoby Ruins Unown, climb Trainer Tower, and document Altering Cave.
Phase 10Cerulean Cave and MewtwoAfter fixing the Network Machine, enter Cerulean Cave, sweep high-level wild tables, and catch Mewtwo.
Major Bosses
| Boss / branch | Team | Reward | Danger notes | Practical counters |
|---|---|---|---|---|
 AdminTeam Rocket | $1728 | The Rocket Warehouse admins are the final Sevii Rocket checks. | Bring Ground/Psychic coverage and heal before taking the second admin. | |
 AdminTeam Rocket | $1760 | The Rocket Warehouse admins are the final Sevii Rocket checks. | Bring Ground/Psychic coverage and heal before taking the second admin. |
Phase Checklist
- National Dex, Celio, Ruby, and Mt. Ember Return: The Network Machine needs both Ruby and Sapphire. Mt. Ember's Rocket path opens the post-game Sevii arc.
- Four Island and Icefall Cave: Icefall Cave requires Waterfall and cracked-ice routing. HM07 Waterfall is inside the cave.
- Five Island, Resort Gorgeous, Lost Cave, Memorial Pillar, and Rocket Warehouse: Rocket Warehouse requires both passwords. Inside, arrow tiles route you through Admin battles before the Sapphire recovery.
- Six Island, Pattern Bush, Outcast Island, Ruin Valley, and Dotted Hole: Dotted Hole requires Cut on the door and a braille-style drop sequence inside.
- Seven Island, Sevault Canyon, Tanoby Key, Tanoby Ruins, Trainer Tower, and Altering Cave: Tanoby Key is a Strength boulder puzzle. Solving it activates Unown encounters in the Tanoby Ruins chambers.
- Cerulean Cave and Mewtwo: Bring Ultra Balls/Timer Balls, status, Surf, and Escape Rope. Mewtwo is Lv. 70 on B1F.