Final Fantasy XI: Chains of Promathia

Final Fantasy XI: Chains of Promathia (also referred as CoP) is the second expansion pack for Final Fantasy XI.

This expansion pack brings several new areas, quests, and a new mission storyline to the game. This is the only Final Fantasy XI expansion that did not add new Jobs.

New Monsters

 * Aern
 * Antlion
 * Biotechnological Weapon
 * Buffalo
 * Bugard
 * Bugbear
 * Cluster
 * Corse
 * Craver
 * Diremite
 * Eft
 * Euvhi
 * Flytrap
 * Ghrah
 * Gorger
 * Hippogryph
 * Hpemde
 * Mammet
 * Memory Receptacle
 * Moblin
 * Phuabo
 * Seether
 * Snoll
 * Tauri
 * Thinker
 * Uragnite
 * Wanderer
 * Weeper
 * Xzomit
 * Yovra
 * Zdei

New Areas

 * Al'Taieu
 * Apollyon
 * Attohwa Chasm
 * Bibiki Bay
 * Carpenters' Landing
 * Grand Palace of Hu'Xzoi
 * Lufaise Meadows
 * Misareaux Coast
 * Newton Movalpolos
 * Oldton Movalpolos
 * Phanauet Channel
 * Phomiuna Aqueducts
 * Promyvion - Dem
 * Promyvion - Holla
 * Promyvion - Mea
 * Promyvion - Vahzl
 * Pso'Xja
 * Riverne - Site A01
 * Riverne - Site B01
 * Sacrarium
 * Sealion's Den
 * Tavnazian Safehold
 * Temenos
 * The Garden of Ru'Hmet
 * Uleguerand Range

CoP also allows the player to challenge Diablos and acquire his summon, though this possibility was not present when the expansion first came out.

Chains of Promathia is considered the hardest expansion in the game. The vast majority of the areas must be unlocked, and most of the said areas have a level cap on them, not to mention enemies that can see/hear through stealth effects. In spite of this, Chains of Promathia is known by some to be the most epic storyline in Final Fantasy XI.