The Monarch of Decay sensed that the prayers to the Malady God were directed at the Origins of Disaster, creating an overlap in identity and offering Him a direct opportunity to seize His target's body.
But He didn't take the opportunity—He wasn't foolish. Killing the Origins of Disaster first and then accommodating the sefirah was the only correct choice!
To seize the other's body now would mean engaging in a battle of consciousness and spirit. The Monarch of Decay wasn't confident of a guaranteed victory at the moment. If He lost, He would end up being accommodated and devoured by the Origins of Disaster, becoming part of that collective consciousness. Moreover, in such a war of consciousness, defeat would mean no chance of escape, given that His opponent was of the same tier.
Thus, any Great Old Dominator with a functioning mind would never take such bait from Lumian.
