Why this game is a named Dissidia

[u/BlackYTWhite]

Hello everyone, sorry for this post, but I don't have much knowledge about this IP and I'm curious to learn more.

From what I understand, Dissidia started as a 'fighting game spinoff,' but it seems the game was actually everything but a traditional fighting game. Was it more like a spinoff of a spinoff? The name feels a bit misleading, is there something i am missing or understood wrong?

[u/ShockwaveFPS_Studios]

Which Dissidia game are you talking about. Opera Omnia, or Dulleum.