The Heavenly Gods possessed the paramount powers of the Heavenly Dao. They were a part of the heavens and were supreme beings. No living beings dared to offend them, let alone eat them!
However, the Chaotic Nightmare Monster had done just that, and it had done so without any hesitation.
Theoretically, no one had the right to eat a representative of the Heavenly Dao.
However, the Chaotic Nightmare Monster was something born from the Heavenly Illusion God's imagination. It was a fictional monster that transcended beyond reality. It was something that had been created after exhausting the power of the Heavenly Illusion God's imagination, and it could not be judged according to common logic.
In other words, the representative of the Heavenly Dao had created something that went beyond its extreme limits. As such, it was going to suffer a backlash.
That backlash came in the form of the Chaotic Nightmare Monster swallowing the Heavenly Illusion God.