Disgaea: Hour of Darkness/Episode X: Angels, Demons, and Humans

Fervent Melody
Most of the map is affected by Invincibility and No Lifting. By standing near the unaffected panels, you can lure the enemies onto them and destroy them without taking damage.

Wasteland of Woe
Not too difficult a battle, just make sure you have a way to cure status conditions.

River of Lava
On this stage there is a Sentinel protected by many Geo Symbol effects. In order to be able to fight him, you will need to destroy all the ones providing a bonus to it and put the Defense-50% Geo Symbols on one of the Geo Panels. Once this is done, it should be no problem to kill the Sentinel.

Searing Tyranny
Most of the enemies here are close together and standing on Exp +100% panels. Destroy them with your best AOE attacks as soon as possible. After they are dead, you may want to lure the remaining enemies onto the panels as well to increase the amount of experience you get.

This is a great place to level up if you find the next stage too challenging.

Inferno
Since mobility in this map is somewhat limited, it may be to your advantage to let the enemies come to you. Mid-Boss should not be much of a threat compared to the other enemies, since he only has single target attacks. Save him for last.