I believe this as well, especially after reading about the War of the First Council, that Vivic especially wanted Nerevar out of the way and layed the blame on House Dagoth.

In ESO we come across the Sixth House in the Forgotten Wastes, where one I think sees the truth of who betrayed who, Nevena Nirith - but what or who was the Statue she was assigned to - that her brother thought to have influenced her. And who might have been the Master Historian she mentions in this journal of hers.

From her Journal:

Some historical accounts have House Dagoth siding with the Dwemer during the War of the First Council, though Vivec's personal account has Voryn Dagoth remain loyal at least until after the Dwemer's disappearance. While the Tribunal were contemporaries of Voryn Dagoth and the Dwemer, they have since vilified both, with Dagoth as the Sharmat and the Dwemer as blasphemers.

After the Battle of Red Mountain, the members of House Dagoth were largely killed, and their children were adopted into the remaining five Great Houses. It's unclear whether this was an attempt to punish House Dagoth for Voryn Dagoth's conflict with the Tribunal over their use of the Heart of Lorkhan, or whether the conflict was less vindictive and was a result of House Dagoth holding out after the Battle of Red Mountain, continuing its opposition to the other Houses. It's also possible to synthesize these disparate ideas, perhaps with the Tribunal declaring that Voryn Dagoth and his retainers had been traitors to the Chimer after his death and the remaining people of House Dagoth believing themselves to be unfairly and inexplicably persecuted--it would not, after all, be the last time the Tribunal would lie to the Dunmer people.

House Dagoth has essentially been struck from Dunmer history. The Dunmer recognize that it existed, but acknowledging that existence is taboo.

Although Voryn Dagoth, Dagoth Ur, slumbers beneath Red Mountain during the events of Online, there have been enough cases of people claiming to be the heirs of the Sixth House since its fall in the First Era to be dramatized in literature, such as Poison Song, which is presumably a work of fiction (though given its scarcity during the events of Morrowind, it may be suppressed by the Temple). Vivec fears his return enough to ask the ghost of Fareno Andrano, "Has the enemy of old returned, so devious and bold?"; it's possible this fear stems from stories of Dagoth Ur exerting his influence despite his apparent death, such as through the cult in the Forgotten Wastes.

Eporem wrote: »

What is known for sure then? is it that Sotha Sil, Almalexia and Vivic did use the tools of Kagrenac, which broke an oath they made to the Daedra Prince Azura, and Dagoth was left behind within the heart chamber of RedMountain - where the beating of the heart is still felt, and now in ESO's time stirrings of Dagoth are being felt - ones of the Dagoth blood line when touching an Ash Statue see a truth they wernt aware of.

and just wonders..

The Blight that would come, would it be similar in a sense that it is focused only on the Dunmer, similar to the change Azura cast on the Chimer in response to the breaking of an oath

The chimes that guarded the entrance in the Forgotten Wastes - are they of Daedric Dwemner or Chimer origin..

and is Dagoth, from where he has awaken able to send his thoughts to others through somesort of tonal communication..

and another thought, when the tools of Kagrenac were used by Sotha Sil, Almalexia and Vivic - did they spilt the heart taking what they thought would make them gods - the light maybe, leaving the dark of the heart which Dagoth might have absorbed.

Yes. Sotha Sil, Almalexia, Vivec used the Tools on the Heart. This is a betrayal to Nerevar, who they promised to that they would not do so. Nerevar is dedicated to Azura (hence Moon-And-Star). Vivec killed Nerevar, though in the Foul Murder the other two are there as well, but absolutely certain Vivec did it at least. Whether Voryn died in the Heart chamber or fled cannot easily be determined, but to me it seems that he never fully died without influence of the Heart. Again, TES5 Solstheim. The paranoia I mentioned is in regards to a woman who had her heart replaced with a Heartstone while alive, causing her death and then re-animation. There is another case— a man who had a Heartstone implanted after death. He is stuck in time and believes he’s forever in the battle that killed him. Considering Voryn has a sense of time, I believe this backs up the belief that even if he did fully die, it was with the Heart influencing him beforehand. The Chimer were not immediately punished, but turned ashen because once the Tribunal Ascended (which I wonder why they were able to but the Dwemer disappeared… I guess has to do with the manner of disappearance) Azura appeared and Sotha Sil proclaimed that the Chimer don’t need the Good Daedra anymore. That’s why Sotha Sil is a Dunmer now, guilt. There’s a conversation in the Mnemonic Planisphere of Divayth Fyr asking why Sil did not remain Chimer.

The Blight is focused on Morrowind however Dagoth Ur seemed to have plans to eventually spread it to all of Tamriel, if not Nirn. Not to evilly take over the world but to “ascend” its citizens.

Dreamer Bells are of the Sixth House, however you bring up an interesting point. If I recall correctly, the Dagoths had connections to the Dwemer, so they may be tonal artifacts. This may explain why they glow red and are able to unlock the door in Forgotten Wastes (though they don’t do anything in TESIII as far as I am aware).

Intriguing thought. It may be possible or it could be because they used the Tools at all. Though, the Tribunal also made pilgrimages to obtain more power, so if they only harvested the “light” they would’ve had to keep some there for future use.

In the Library of Andull the Librarian Bradyn states that the genealogies of the Great Houses date back to before the War of the First Council - only five are there and not of House Dagoth, - if this was before the War of the First Council, why would they not be. If their genealogy record was removed and the Chimer spirit that represented them banaished - I just question what was it that needs to remain hidden, and since the genealogies are written in a script that the Librarian has to deciper I don't think it ever to be known. I do think though that there was one written of House Dagoth and it was this that was revealed to Nevena Nirith which made her forsake her acceptance into the Tribunal Temple to join the Sixth House.

ah well - maybe within the realm of Apocrypha more will be revealed

Eporem wrote: »

so other wonders/questions that come from reading this lore book:}

......

As Azura had Indoril Nerevar as her champion/avatar?, did the other two good Daedra that the Chimer followed, Boethiah and Mephala, have ones as well? Was Veloh - Boethiahs champion and could Dagoth have been this for Mephala maybe. Is/was Mephala the anticipation of Vivec, Azura the anticiption of Sotha Sil and Boethiah the Anticpition of Almalexia - What do Anticiptions in this sense mean - that they (Vivec, Almalexis and Sotha Sil) were prophesied/promised to become powerful like these Daedra? and decided maybe they no longer wished to?

Also from this lorebook, are the Velothi Prophecies that are mentioned known at all from any of the other games.

and...

This Ritual Table of the Sixth house have letters in Daedric script I believe, as are the chimes in the Forgotten Wastes?. Do they both spell out Dagoth in Daedric script.

"As Azura had Indoril Nerevar as her champion/avatar?," - Yes.

" did the other two good Daedra that the Chimer followed, Boethiah and Mephala, have ones as well? Was Veloh - Boethiahs champion and could Dagoth have been this for Mephala maybe." - Not that I know of, though I think Vivec was also affected by Boethiah and given symbolic/metaphorical black hands? Something to look into.

"Is/was Mephala the anticipation of Vivec, Azura the anticiption of Sotha Sil and Boethiah the Anticpition of Almalexia - What do Anticiptions in this sense mean - that they (Vivec, Almalexis and Sotha Sil) were prophesied/promised to become powerful like these Daedra? and decided maybe they no longer wished to?" - Anticipations are that they replaced the Good Daedra in now Dunmer worship. The spheres of the Good Daedra are inherited to their Anticipation in the Tribunal for the Dunmer.

"This Ritual Table of the Sixth house have letters in Daedric script I believe, as are the chimes in the Forgotten Wastes?. Do they both spell out Dagoth in Daedric script." - Forgotten Wastes spells out "DREAMS", at least that's what glows red on the wall. As for the table, that one does spell Dagoth.