Seems like we may know the 3rd round of DLC already

[zferolie.livejournal.com]

Posted by Unknown)PC on Gamefaqs.

JP Wiki page updated with some 3rd round info, they didn't state their source however.
http://alphawiki.net/disgaea4/index.php?%A5%D1%A5%C3%A5%C1%A1%A6DLC#vff1f789

Tournament Battle (600 yen)
- Fight consecutive 10 battles against user pirates
- Unlocks Plenair with certain conditions

Main Hero B (300 yen), also allows creation of celestial host humanoid class

Prism Red (300 yen)

Map - Gargantuan Deck (100 yen)

Gargantuan ship parts (200 yen)

Toro Bow (free)

Free custom theme of Prism Rangers