Vivec and Guilt
I have been thinking very hard about Vivec. Vivec often gets the term "Mary Sue" slapped on him by others and, until recently, I used to agree. Then I realized that Vivec is actually a deeply human (despite not actually being so) character who, quite contrary to the Mary Sue spirit, has very deep character flaws and suffers from the consequences of his actions very often (at least before the Trial).
Early Life
I'm sure that by now most of you are familiar with Vivec's history, but I'll reiterate it here just in case.
Vivec was born as a prostitute in the slums of Mournhold and, through a series of events, grows to become Nerevar's closest confidante. It is stated that Vivec loves Nerevar and implied that he loves him in a more-than-brotherly way, something which I leave purely up to your interpretation.
Come Red Year, when the Dwemer wish to abuse the Heart of Lorkhan's power to achieve apotheosis. The Dunmer successfully stop their plans, but their leaders have their own designs for it...
Foul Murder
Despite his oath to Azura, Vivec attempts to tap into its power. This raises the ire of Nerevar, who wishes to remain loyal to Azura. Seeing that his best friend is in his way, he has no choice but to kill him for power.
I think Vivec was far from remorseless when he did that. The hidden confession in the 36 Sermons, I think, isn't just an example of Vivec being a cryptic asshole. I think it was an admission of guilt, an admission that he was on some level aware of his responsibility for Nerevar's death.
So frustrated by this is he that he rewrites history using CHIM to make it so that he was innocent of Nerevar's death. I think this is a sign that he felt even worse about it than Sotha Sil ever did. While Sotha Sil managed to accept his responsibility, Vivec denies his, creating a "half-guilty, half-innocent" compromise that eventually becomes his entire persona.
Growth and Decline
With his divinity and his innocence secure, Vivec then launches the longest smear campaign in the history of Tamriel against Azura. He knows there's no turning back now. This will come back to bite him HARD later, as we will see.
Vivec does not anticipate the creation of Dagoth Ur, a by-product of his betrayal at Red Mountain. Dagoth Ur successfully captures the Heart for his own purposes, weakening Vivec's powers severely. Weakening, but not destroying.
It takes the Nerevarine to do that.
Thirsty for revenge, Azura sends Nerevar's spirit in the body of another mortal. This leads to a series of events that successfully recreates pre-Tribunal society and basically undoes everything Vivec had worked for until then. The final nail in the coffin is the destruction of the Heart, which permanently rids Vivec of his Lorkhan powers.
By betraying Dagoth Ur, Vivec creates a chain of events that lead to the Heart's power waning. By killing Nerevar and spiting Azura, he makes enemies who eventually destroy his main source of divinity. Vivec becomes the classic villain whose undoing results from his past deeds.
Vivec is far from a Mary Sue in the classical sense: he is a character who does horrible things to get what he wants and suffers greatly for them.
CHIM
The theme of the inability to be free from the past even shines through in one of the most important aspects of his character, that of CHIM. CHIM was not the final phase that Vivec had to go through. He still needed to attempt Amaranth, and tries to do so:
><MK> Sermon 19. What does Vivec do?
><MK> He makes the Provisional House. He attempts the Dream.
><MK> He is answered with a song
><MK> a poem
><MK> He's not ready for his own answer
><MK> Looking at every Corner
><MK> Hiding in some new thing he made to survey this new House he can't make
><MK> That's the tremble of "I"
><MK> "This house is safe now
><MK> "--so why is it"
><MK> He knows right then he can't make that jump
><MK> He can't commit to that marriage
><MK> More:
><MK> he's afraid of all the "catastrophes in between"
What does this mean? My interpretation of it is - Vivec's deeds have created for him a past that he cannot let go of, a past plagued with guilt and remorse. This past is inextricably linked with Mundus and the Aurbis as a whole, and so by extension he finds himself unable to let go of that too. Vivec fails to reach the end-goal of the Mundus because he has become too attached to it as a result of his history.
Vivec is a self-admitted liar, and the biggest lie he has ever told is this: he convinced us that he had ascended to a state of being beyond our comprehension, but in the end was just as firmly rooted here as we were.