This sparked by a thread on the battlefield.

I think almost every cabal should be at constant war with Nexus, except Tribunal and Scion. Essentially anybody whose goal is a perpetual state that Nexus would attempt to thwart should consider the Nexus an enemy. Tribunal is an exception because their status quo is basically the same as the balance Nexus wants to keep. Scion is an exception because once they trick the Nexus into helping them bring the eternal night, there's no going back (plus Scion is just devious and likes to use people).

Now it certainly makes sense for Nexus to be a lower-priority target for a cabal like Fortress. But since the Nexus is ultimately trying to half-fill the world with evil, the Fortress should want to destroy them as an entity. Individuals may choose whether they wish to attack Nexans on sight (someone could decide that persuasion is the right approach for neutrals). Similar logic applies to the other cabals.

Not that it matters, but I actually am one of the few (or silent many) that like the Nexus. So it's not animosity towards Nexus that is motivating this, I just think it makes RP sense.