Ghost Commander's Key

Type: Key
Cannot be used in battle
Effect: Our nation/guild can enter Ghost Ship of the Caribbean.
Guild level must be higher than 30
Fixed Price: n/a

You can enter the Ghost Ship of the Caribbean dungeon.
(The Ghost Ship of the Caribbean only allows 7 mercenaries on board.

Source

NPCs

Name	Trade For	Quantity
Pointry	Guild Points x 3,000	1