The next installment of Disgaea 4: A Promise Unforgotten downloadable content adds a challenge mode to the Item World plus Lord Zetta's daughter, Peta.
Disgaea 4: A Promise Unforgotten has more downloadable content coming, but instead of guest characters Nippon Ichi hired guest artists to create new classes for the PlayStation 3 game.
Disgaea 4 is about Valvatorez, a vampire who has sworn off human blood in favor of sardines. It's also more welcoming of newcomers who aren't familiar with its predecessors.