Disgaea: Hour of Darkness Tips

Etna's Secret Room
To access Etna's secret room, click behind the throne. Then go to the skull on the counter of the armor shop and click on it as well. Now in the room with Longinus, click on the corner and Etna will say that she has to go to the bathroom.

If you read the entries for each chapter in their respective chapter, you'll receive Testament after the Final Episode.