Gravis and Mortis concentrated on all of their insights.
Back in the higher world, it had been an impossibility to comprehend the Law of the True World.
Why?
Because comprehending it required some knowledge about the deeper workings of Energy.
Now, as Peak Divine Gods with all the True Laws, Gravis and Mortis easily had this little bit of insight. It wasn't an entire Law all on its own, but just a very advanced principle of Energy.
If one didn't know enough True Laws, one wouldn't be able to extrapolate that principle since one was missing too many points of reference.
But, of course, knowing all the True Laws was more than enough.
Cultivators that didn't know that principle would find an issue in combining everything.