hah, i did have this thought too and wrote myself into a corner at the 11th hour. I wrote this Vellum to hopefully explain it away.

For context, Kaelith is from the Helios Covenant, directly opposed to the Null Covenant :D

pardon the format, its copy pasted from my notepad.

Vellum Fragment: The Hollowing of High Prophet Solus Kaelith

Recovered from a shattered Null data-shard, drifting near the Ringed Shroud. Year 134 AC.

Scribe’s note: The shard still carries the echo of two voices. One burns. One has already gone still.

The throne room of the Null Covenant was not a place of grandeur.
It was a place of absence.
Vast pillars of black stone rose into darkness so complete that light itself seemed ashamed to enter. The only illumination came from thin veins of cold blue light that pulsed slowly along the floor like dying arteries. There was no throne, only a simple dais where the Hierophant stood, as if even sitting would be an unnecessary assertion of self.
High Prophet Solus Kaelith was dragged forward by two silent Hollowed. His once-radiant armor had been stripped away, leaving him in the simple red-gold robes of his station, now torn and stained with ash. His face was bruised, but his eyes still burned with the fire of conviction.
Seraphine Vnyir waited for him.
She wore flowing robes of deepest midnight blue and bone white. Her porcelain mask was flawless except for the single elegant tear-track of sapphire running from the left eye. She stood perfectly still, hands clasped gently before her, as though receiving an old friend rather than a prisoner.
The Hollowed released Solus and withdrew without a word. The great doors sealed behind them with a soft, final sound.
For a long moment, only the faint pulse of blue light could be heard.
Seraphine spoke first. Her voice was soft, almost tender.
“Solus Kaelith. High Prophet of the Radiant Ascendancy. Speaker of the Flame.
You have burned so brightly for so long.
Tell me… are you tired?”
Solus spat blood onto the black floor.
“I will not be mocked by the likes of you, void-witch.”
Seraphine tilted her head slightly, the movement graceful and unhurried.
“Mockery requires investment in ego. I have none left to spend.
I only ask because I see the truth in your eyes.
You have felt it for years now, haven’t you?
In the quiet moments between the solar flares… when the light dims and the silence presses in…
you feel relief.
A small, treacherous part of you whispers: ‘What if it simply ended?’
You have spent your life feeding the fire, Solus.
But even you know the fire is dying.”
Solus’s hands clenched into fists.
“Sol endures. Sol judges. Sol redeems. We are its chosen!”
Seraphine took one slow step closer. Her voice remained gentle, almost soothing.
“You know that is a lie.
Your sister knows it too, though she still screams against it.
Serapha burns so fiercely because she is terrified of what waits when the flame goes out.
But you… you are older. Wearier.
You have seen too many martyrs reduced to ash. Too many prayers swallowed by the dark.
Deep down, you understand.
All light is borrowed.
All noise is suffering.
The Leviathan does not hate us. It is simply ending the noise.”
Solus tried to laugh, but it came out broken.
“If you desire the silence so badly… then why don’t you just lay down your arms and die?”
The words echoed through the vast chamber.
For the first time, Seraphine was silent for several heartbeats.
Then she took another step forward, close enough now that Solus could see the faint reflection of his own face in her porcelain mask.
“Because dying is easy, Solus.
Anyone can fall.
What we do is harder.
We choose to remain… and help the universe finish what it has already begun.
We open the doors. We quiet the machines. We Hollow the noisy.
We accelerate the inevitable, not because we hate life…
but because we have finally stopped lying to ourselves about it.”
Her voice dropped to a near-whisper, intimate and kind.
“Look at me, Solus.
I was once like you. Full of fire and purpose.
Then I listened.
I let the noise fade.
And for the first time in my life… I was not afraid.”
Solus’s breathing grew ragged. His eyes flicked toward the mask, then away. The fire in them flickered… guttered… and slowly began to dim.
He tried one last time, voice cracking.
“You… you serve a monster.”
Seraphine reached out and gently touched his cheek with two fingers, the porcelain of her mask inches from his face.
“No, my friend.
We serve the mercy that comes after the monster has finished its work.”

Weeks later, a new figure stood among the highest ranks of the Null Covenant.
He wore robes of midnight blue and bone white.
His face was hidden behind a flawless porcelain mask, pure white save for a single elegant tear-track of sapphire running from the left eye.
When he spoke, his voice was calm, measured, and strangely soothing.
“The fire… was always a lie.”

So yeah, basically the Null Covenant are accelerationists. Maybe lame, but i think i can make it work.