Disgaea 2: Cursed Memories/Land of Carnage

The Land of Carnage is unlocked after collecting all 16 Treasure Maps from the Item World. One the pieces are collected, talk to Hawkeye the Collector in Holt Village to take you to the Land of Carnage. (You can return to Holt Village again by talking to Hawkeye again.) Upon arriving, you will receive a legendary Longinus spear (if certain items are on hand upon entering).

Recruitment
In this other world, Axel, Fubuki, and Kurtis can be recruited for use ONLY in the Land of Carnage (they will leave the party if you return to Holt.) Axel can only be recruited during Episodes 3, 9, and after the story map "Final Decision." Fubuki can be recruited only after completing map 13-3. Kurtis can be recruited immediately.

Enemies in the Land of Carnage are much stronger than their Holt counterparts, especially if "Stronger Enemies" proposals are passed. It is useful for leveling up your troops for the post-game.

The Item World
The Item World is also different in this realm. If you enter the Item World from the Land of Carnage, enemies will have Geo Effects within them, seperate from the Geo Symbols already laying around. Whenever they move, the panels they move over will be overwrtitten with the same colors/effects that the enemies that moved had. (Example: Wood Golem with Damage 20% moves 3 panels forward, the panel he was on as well as the panels he moved upon will now have Damage 20% effect.) Defeating these unique enemies may spark a Geo Chain upon their defeat.