Having already had conquered and subjugated pretty much everything in their entire known universe for thousands perhaps even millions of years and integrated it all into one vast empire, this left the factions somewhat at a loss for where to go next from that.
The moderates amongst them, they realized that the only place left to conquer was inside oneself, and through the brutal tools of cybernetic grafting and personal gene modding they went about trying to carve themselves new forms as a means to go about self-improvement with the same ruthless efficiency as their ancestors had when "settling" the negaverse.
The reactionaries, believing themselves to already be perfect and perhaps indeed the closest still living link to their divine NoRunners as well as Kellek himself, through twisted reasoning, found this approach as adopted by the moderates (of limiting the conquering to improving upon yourself instead of ones neighbors) to be downright disgusting. If nothing outside remained to be conquered, which was impossible, then one simply has to start over, and reconquer. Somehow. The (large) opening of a gateway between our two dimensions has served as a force to awaken this long dead theologic conflict... as a massive mutated crusade between moderate and extremist shakes the core of Antihuman society.
Where the rat people fit in with this is far more mysterious. They are enacting a very ancient protocol, in essence unknowingly behaving as living software resources, making the system environment for a primordial program that was established to try and solve their dimension's environmental problem from long ago.
What lies at the core of these three set ups though... and why it is that the rat people seem to be much less affected by the pollution than their mutant Antihuman neighbors, are things that remain to be figured out.
Submitted by Mycobacter#712744