Maybe I haven't looked hard enough, but I haven't found a direct summary of what the Enantiomorph is, or its significance. The lore buff sticky provides but scant information.

From what I have read, I understand it's a story about a Rebel who betrays the King and takes his place, with the former King eventually exacting vengeance. This narrative is echoed frequently in the Elder Scrolls, but I'm unsure of it's importance. I really need to read the Sermons of Vivec, I'm guessing.

Does Miraak play into this narrative? How about Jagar Tharn?

An Enantiomorph is a cosmic event that results in the creation of a powerful object or thing. It involves around Three Key Players, but in truth there are Five:

1. The King (Warrior) – The King functions as the person who is in control and the greatest power in the known universe. He is trying to dispose of the Rebel.
2. The Rebel (Thief) – The Rebel is the individual that comes to wrestle control from the King and then become the new King.
3. The Observer (Mage) – The Observer has the most important role in the Enantiomorph, being the only one who can differentiate between the Rebel and the King (1 and 1) and decide the result to the Enantiomorph. This unique role usually leaves him maimed in some form or fashion because of the cosmic event, and then redraws from the Catalyst.
4. The Catalyst (Nirn) – The great and immensely powerful thing created by an Enantiomorph, examples include Nirn and Convention 2.0
5. The Prisoner (Hero/Serpent) – The Prisoner is the person who ignores the Enantiomorph taking place but plays a key role in it, as its usually his or hers shenanigans revolving around the Catalyst that can interfere with the plans of the Rebel and the King. Can be considered a secret weapon.

Do you have a source for #5? MK's classic explanation only has the first four roles, not to mention it doesn't fit with the entantiomorphs we know already. (Who is the hero in Anu/Padomay, Lorkhan/Akatosh, or Hjalti/Wulf/Arctus? Or how about the fact that Nerevar is the betrayed King? Or that Sharmat/Nerevarine is Rebel/King?

As far as I see it, the "prisioner" who takes part is part of the Witness role, while the "hero" - as in player-character anologue - can fill any role - usually rebel or witness.

OP:

The significance is that it's a repeating pattern - archetypes are part of what makes the Aurbis tick, in a metaphysical sense. By tapping into powerful myth-types, the denizens of Tamriel can get certain powerful outcomes based on what has played out before. The enantiomorph is particularly potent because it is the myth of creation itself. It has repeated many times, starting with a betrayal between Anu and Padomay, which created the current dream, then repeating with the betrayal between Lorkhan and Akatosh which created Convention/Nirn, and finally being repeated by mortals in the Red Moment and in the creation of Talos.

Those who act out the enantiomorph are creating an association between the beings of convention and themselves. For example, Hjalti Early-Beard betrayed Wulfharth through Zurin, mirroring the removal of Lorkhan's heart at convention and allowing his trapped soul to function as a replacement for the heart of Lorkhan. This is why their combined soul, Talos, became a replacement for Lorkhan, mythically, and why Numidium was able function without the Heart.

So, it's not an Enantiomorph without a Catalyst, then? The Imperial Simulacrum seems to have a lot of parallels with the Enantiomorph, and although it's not mentioned in the http://www.imperial-library.info/content/rebels-return I can't help but feel that's deliberate. But I can't think of what the Catalyst could be.

We've got the King, Uriel Septim VII. Jagar Tharn is the Rebel, who uses the Staff of Chaos to banish the Emperor and literally become him, taking the place of the King. Ria Silmane takes the role of the Observer; she's the only one who knows of Jagar Tharn's betrayal, and is obliterated by Tharn for knowing. The Prisoner is obviously the Eternal Champion.

It's a bit harder to fit Miraak into these roles, but I like Miraak so let's see if it's possible. http://www.imperial-library.info/content/guardian-and-traitor sets it up: Miraak the Rebel/Traitor fights against Vahlok, the Guardian/King, and is whisked away moments before defeat by Herma-Mora, who represents the Observer (and yet doesn't get maimed as far as we know, but who could tell with an eldritch abomination).

OR. Miraak is actually the Prisoner; Akatosh is the King, Alduin is the Rebel, (who's the Observer?) and Miraak (and then the Last Dragonborn, after Miraak fails) is the "Wild Card", a character unbound by fate who has the potential to tip the scales in the direction that saves the universe. I've http://www.gamesas.com/topic/1505482-could-miraak-have-been-a-hero/ that Miraak could potentially be a Hero who never bothered with his "destiny", similar to the Failed Incarnates of the Nerevarine prophecies. It's worth mentioning that the aforementioned Guardian was named Vahlok the Jailer.

My one thread from a while back, just posted on the forums http://www.gamesas.com/topic/1508358-the-importance-of-the-prisoner-why-tes-heroes-are-dikes/ Its more or less pure speculation, but hell. The Prisoner = The Hero.

Where exactly can I find this classic explanation? I can almost never find any relevant Enantiomorph info in sources.