Baal, The Super Overlord - Disgaea 7

This video covers the boss fight against Baal, taking place after completing the main game. Here are the timestamps and notes.
0:00 The group arrive in Baal's lair
1:35 Boss fight
5:49 After the fight, the group manage to deal with Baal
8:14 After beating Baal, you can get his sword by Netherworld Sightseeing his stage