Ancient Caustic Sewers

Ancient Caustic Sewers, also known as ACS, is the continuation dungeon of Caustic Sewers. It is void of weather like Caustic Sewers.

Attributes

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The dungeon is light green in color, there's rather heavy darkness and rooms are usually very compact and small. Water continues to poison Pokémon who are not immune or protected from it.

On Floor 15 is a sealed chamber with a Sinister Box that can contain the following items:
 * Pink Silk
 * Big Nugget

Boss
The player finds Team Skull, a Reuniclus and three Solosis at the end of the dungeon. Reuniclus and the Solosis are accused of causing the leakage in the sewers because of the substance that covers their bodies. The Reuniclus was unaware of the leakage issue and has no connection, and the player interferes with Team Skull to prevent any harm done to the Reuniclus in spite of that.

Unlike Caustic Sewers, Team Skull has the following moves in Ancient Caustic Sewers:
 * Koffing: Dark Pulse, Facade, Sludge Bomb, Thunderbolt
 * Skuntank: Flamethrower, Poison Jab, Shadow Claw, Throat Chop
 * Zubat: Aerial Ace, Leech Life, Shadow Ball, Venoshock

Boss drop:
 * 30 Ekop (Skuntank)
 * Skull Brooch (Zubat)
 * 1 Mushroom (Zubat, Koffing)

Forgotten Shrine
In the end room there are two Deluxe Boxes.

Box items:
 * Purity Relic
 * Poison Dust
 * Full Restore
 * Max Revive
 * Old Gateau
 * Big Nugget
 * TM Sludge Bomb
 * TM Poison Jab
 * TM Venoshock

Secret Room
The Secret Room contains two Deluxe Boxes, and it is found on all floors besides the last.

Box items:
 * Poison Dust
 * Golden Apple
 * Revive
 * Revival Herb
 * Big Nugget
 * Relic Vase
 * TM Sludge Bomb
 * TM Sludge Wave
 * TM Toxic
 * TM Venoshock

Pokémon
''Pokémon in bold are recruitable. Please visit the Recruitable Pokémon page for more information.''


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Items

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Kecleon Shop Items
There is a Kecleon Shop on Floor 12.


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Mystery Eggs
Ancient Caustic Sewers has Mystery Eggs that can appear on all floors.


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Dungeon Objective
The Purity Relic and Skull Brooch are both items exclusive to this dungeon. A Pink Silk can be obtained here alongside Caustic Sewers. Players often come to this dungeon to earn Ekop for the various shops in the Tanren Undercity.

Tips

 * A way to heal or prevent statuses (mainly poison) is recommended.
 * As with Caustic Sewers, beware of Garbodor and Skuntank's Aftermath ability.

Trivia

 * This is the highest level dungeon in Tanren Undercity.