Yet only the Champion of Cyrodiil was "Accepted" by Sheogorrath. All others were driven hopelessly insane. If anything, the strongest source of lore indicates that the Champion of Cyrodiil and the Guy who Became Sheogorrath are one and the same - The game only lets you play as one person. There's no way, in the base game, to switch between The Guy Who Became Sheogorrath and The Guy Who Saves Tamriel. NPCs will call you all three titles - Champion of Cyrodiil, Madgod, and Divine Crusader. All three were the same person.
The way Sheogorrath spells it out leaves no ambiguity. Especially given precedent from previous games. The only game in the series that doesn't make EVERYTHING the PC does canon to that character is Daggerfall, and that's because, aside from the Main Quest, all quests are superfluous anyway. And with the main quest, the problem isn't "We don't want to say the Player Character did beat the game". The issue was that Daggerfall had EIGHT equally-viable, mutually exclusive endings. They didn't say "He didn't give it to Gortwog, because he may have given it to the Underking". They said that he did everything - even to the point of it not being possible in-game.
"My Agent of the Empire didn't give the Mantella to Gortwog" Actually, (s)he did (Otherwise, orcs would not be a playable race). AND Mannimarco (Otherwise, there would be no Necromancer's Moon). AND the Kingdoms of Daggerfall (Otherwise, Wayrest would rule all of High Rock), AND the Kingdom of Sentinel (Otherwise, High Rock would have conquered Hammerfell), AND the Kingdom of Wayrest (Otherwise, Daggerfall would rule all of High Rock), AND the Empire (Otherwise, High Rock and Hammerfell would have been independent), AND the Underking.
Saying that the CoC and Sheogorrath are not one-and-the-same for whatever reason is like arguing that the guy who re-discovered the Numidium and Mantella, and the Guy who exorcised Lysandus' ghost were not the same because of "lack of evidence" explicitly saying they were.
Or, that the guy who killed Almalexia was not the Nerevarine (It's just rumor that the Nerevarine was the one to kill Almalexia)
That is what's written in the Elder Scrolls.
I'll start again - Whoever became Madgod, by evidence within the game itself: A) Had to return the Amulet to Jauffre (And therefore find Martin, and from there do the rest of the Main Quest), or carry the Amulet with him, until such time he has to become Champion of Cyrodiil before the Daedra completely take over the world.
The way Sheogorrath spells it out leaves no ambiguity. Especially given precedent from previous games. The only game in the series that doesn't make EVERYTHING the PC does canon to that character is Daggerfall, and that's because, aside from the Main Quest, all quests are superfluous anyway. And with the main quest, the problem isn't "We don't want to say the Player Character did beat the game". The issue was that Daggerfall had EIGHT equally-viable, mutually exclusive endings. They didn't say "He didn't give it to Gortwog, because he may have given it to the Underking". They said that he did everything - even to the point of it not being possible in-game.
"My Agent of the Empire didn't give the Mantella to Gortwog" Actually, (s)he did (Otherwise, orcs would not be a playable race). AND Mannimarco (Otherwise, there would be no Necromancer's Moon). AND the Kingdoms of Daggerfall (Otherwise, Wayrest would rule all of High Rock), AND the Kingdom of Sentinel (Otherwise, High Rock would have conquered Hammerfell), AND the Kingdom of Wayrest (Otherwise, Daggerfall would rule all of High Rock), AND the Empire (Otherwise, High Rock and Hammerfell would have been independent), AND the Underking.
Saying that the CoC and Sheogorrath are not one-and-the-same for whatever reason is like arguing that the guy who re-discovered the Numidium and Mantella, and the Guy who exorcised Lysandus' ghost were not the same because of "lack of evidence" explicitly saying they were.
Or, that the guy who killed Almalexia was not the Nerevarine (It's just rumor that the Nerevarine was the one to kill Almalexia)
That is what's written in the Elder Scrolls.
I'll start again - Whoever became Madgod, by evidence within the game itself: A) Had to return the Amulet to Jauffre (And therefore find Martin, and from there do the rest of the Main Quest), or carry the Amulet with him, until such time he has to become Champion of Cyrodiil before the Daedra completely take over the world.
Ill accept your argument about the acceptance of Sheogorath.
Yet again, there is no source that says it has to be the CoC.
It could have been any soul with the correct aptitude.
There is no reason to assume that the person who had the amulet actually went through the portal.
That you did in the game is no excuse, for the exact same reason you mention the different endings of Daggerfall.
When it comes to the Nerevarine killing Almalexia, this is different.
The Nerevarine was the only one with such power, the only one directed by Azura, and later accounts place him at Mournhold during the time of the fabricants. When it comes to him going to Solstheim, again, I find that debatable.
There are no accounts that do similar for the CoC.
What Sheogorath says can be interpreted differently, it really isnt hard as his actual lines are very ambiguous.
Your point about the acceptance of the madgod being paramount as to not being driven bat-[censored] crazy Ill accept as a strong point towards the CoC being the mantler, but it is still conjecture.
My main objection with the person(s) in the game doing everything in the game as canon is that I find it boring and therefore wrong. I just find it unacceptable from a story-telling perspective.
The lore of Tamriel is always ambiguous enough for many interpretations and this is no exception.
Its quite possible that is is true, but there just is no evidence.