One Must Fall/WMG

The Four Bad Band of Tournament Mode are...
Ian Tavares as the Big Bad, Nicoli as The Dragon, Jaqouline as the Dark Chick, and Raven as The Brute.
 * Or, if you want to look at it from another angle and assume Jaqouline, Nicoli and Tavares were employees of Kreissack alongside Raven, then...Kreissack, naturally, would be the Big Bad and Raven The Dragon; Tavares would be The Evil Genius; Nicoli, The Brute; and Jaqouline, the Dark Chick.

The Nova was downgraded to be just like the other HARs .
Because otherwise why would Ian Tavares be using it as the boss of the World Championship tournament? .

Either Shirro or Ibrahim won the tournament, which is why WAR as a company and a concept still exists but now has more of a sports theme behind the HAR battles.
This would fit better with Shirro's ending in Story Mode, but Ibrahim's motivation is just as likely. Explained in further detail in the points immediately below.
 * This guideline site provides quite a bit of information that supports this WMG, based on the timeline provided from the game's manual and input from the creators themselves. For instance, this page on the question of who won Ganymede gives the strongest support for the idea that either Shirro or Ibrahim won, and then the two collaborated to orchestrate WAR and the timeline of what we know as Tournament Mode (their respective goals in their endings could conceivably work together, plus in-game they're established as friends).
 * Alternatively, the same site provides a link to information from a datacube in fellow Epic Megagames creation Tyrian which hints that Steffan won control of Ganymede, though the datacube in question portrays him as a Jerk with a Heart of Gold. The datacube info can be seen here. The site itself acknowledges that it's not certain that the two games share the same continuity and the Steffan datacube could simply be a Shout-Out (but the possibility of a similar continuity isn't ruled out either).
 * It's possible that Shirro was the overall winner, but kept Ibrahim and possibly Cossette around due to their experience with HAR design, and assigned Steffan to man Ganymede on WAR's behalf. It's also quite possible that Shirro kept the following people in positions at WAR: Crystal and Christian, due to their father's previous position there; Jean-Paul, due to his brilliance; and Milano, due to his hidden legacy connected to the company WAR used to be under his father's influence.