An announcement trailer can be seen below.
The Complete+ edition of the game includes all content found in all previous versions of Disgaea 4, including scenarios that were newly added in the PlayStation Vita release at the time. Disgaea 4 Complete+ on PC will feature various network features, but these are set to come at some point after launch. NIS America has posted blog entry outlining the things we can expect, such as a map editor and Netherbattle tournaments.
Map Editor: Users can arrange terrain, characters, and objects to create their own original, unique maps. The ability to upload their maps and play other users’ creations will be available early 2021.
Pirates: Users can combine ship parts and arrange characters to create an original pirate ship and crew, then upload their pirates to fight other players. Additionally, uploaded pirates can also show up in the Item World to either attack or support the player that encounters them!
Foreign and Defense Ministers: Users can appoint a “Foreign Minister” to appear in other players’ Dark Assemblies to sway the voting process, and summon another user’s “Defense Minister” to help them in battle.
Netherbattle Tournament: Users can upload their characters to four classes and challenge unique online stages by creating a battle party with other players’ characters.
Everybody’s Netherworld Records: Players can upload their data to contribute to 12 stat categories that compile everybody’s total progress.
Pirate Trial: Users can engage in trials with their Pirates and upload their results for ranking and receive rewards the following week depending on their ranking.
Ranking Battle: Users can engage in a themed battle (themes are rotated weekly) and upload their score to the ranking boards. Ranking Points (RP) will be awarded according to the user’s ranking, which they can exchange for items at the Ranking Shop.