[Speculation] The Naaru attacking Revendreth ended Denathrius' plan for the Nathrezim

[Khahirr]

The key mistake the Nathrezim/Denathrius made was assuming the Nathrezim could not succumb to the forces they were attempting to subvert.

There are several clues pointing towards the failure of the plan:

- The Accuser's dialogue with Denathrius in the quest "A Lesson in Humility"

Sire Denathrius says: Perhaps a few centuries burning in the Ember Ward will remind you of who rules this place.
The Accuser says: Even your punishments reveal your complacency. Very well. Hide me with your other failures.
The Accuser says: You were once the lord of dread. Now? Now your teeth have lost their terror.

- The Spire of the Unseen Guests (Nathrezim) is in the Ember Ward and contains the journal Enemy Infiltration that details the plan for infiltration of each cosmic force. The journal is in the container "Lost Journal" which implies this is old information and to be left in the tower it must no longer be of importance. Enemy Infiltration also claims that in order to subvert the Light the Nathrezim would have one of their agents join it (i.e. Lothraxion)

"They savor nothing more than being proved right, so if they believe they have converted one of us to their precious Light, they will trust that agent implicitly."

- The Naaru Z'rali's dialogue in Revendreth

"Home. It calls to me, mortal. And yet, I will never know its warmth again.
My kind would not perceive me as I was. They would see only an aberration. Fractured. Tainted by the touch of this realm's dark Master.
Now there is but one path before me. To ensure the Light is felt here. That justice is rendered. And that Death is made to know its place.
So here I remain. Bound by duty. Until my last flicker fades away."

"We came seeking justice. Retribution. To answer an affront committed upon the Light itself.
Our numbers were vast. Uncountable. Every heart burning with righteous fury.
Many fell. But not before we unleashed a fire that our enemies could not endure. The seething scar of our vengeance still lingers in the firmament.
I lay broken on the battlefield. Until the unseen ones found me. Preserved me. To serve as a vessel for their Sire's rage."

This last bolded bit in particular shows the Naaru are aware of the Unseen Ones which would imply they likely know what their plan was.

- There are no actual Nathrezim anywhere in the Shadowlands that we have seen. Only the Stoneborn which look similar but have a different purpose.

- The light can be forced upon others through lightforging, which may remove their free will. See: some Mag'har orcs from AU Draenor (Lightbound), the attempted conversion of Illidan



So with all this going on, what happened? The Nathrezim assumed that they could resist being bent to the light's will, or at the very least that they could hide their deception. So they send Lothraxion to be their man on the inside, only for him to end up lightforged. Now does he end up lightforged before the attack on Revendreth or after I cannot be sure. But either way I think the Naaru found out about Denathrius' master plan for the Nathrezim through Lothraxion and promptly invaded Revendreth to mete their vengeance against the force that sought to use their "singular purpose" against them, so they could "learn their place". As a result, Denathrius loses a quarter of his realm and his Unseen Guests project.

What does the failure of the Unseen Guests project mean? I'm not entirely sure, but I speculate that any remaining Nathrezim are not actually still working for Denathrius. I speculate following the destruction of the now "Ember Ward" death is put in its place so to speak and he abandons the project and severs connection with the Nathrezim so as to not tempt the wrath of any other cosmic forces. This may even be what led him down the path of joining the Jailer to achieve his ends.

In reading Enemy Infiltration we are not reading a plan that succeeded and set the current events in motion, we are reading a plan that FAILED and set the current events in motion as a result.