After reading some recent discussions I came again to think about Sheogorath, Arden Sul, Jyggalag and the PC and how it all came together (or not for some). In my opinion, SI is actually very interesting lore wise (compared to Oblivion at least) and has found ways to describe a dragon break coming from a gods ascension (and then there's the native grummites etc.).

There are 2 main theories about what happened at SI:
1. The PC mantled Sheogorath, became him, Jyggy went on vacation and everyone is happy.
2. The PC is bat[censored] crazy and it's all a trick.

There were attempts before this post to unify these two and say "the PC is bat[censored] crazy, but he did mantle Sheogorath". That's the path I'm taking but there's more. For most lore buffs the main problem is the ending.

When Jyggy appeared at the end and gave his speech, most people who thought they understand the isles/lore thought it was some sort of Bethesda screwup. And perhaps it is but I have a theory which makes it sensible with everything else.

Now first lets establish what actually happened:
The PC went into the isles (as a mortal obviously). He got past the gatekeeper and managed to get hired by Sheogorath himself to do bat[censored] crazy stuff. Stuff which happened to be also the road to mantling the big man himself.

When that happened, a dragon break occurred (sort of, let's not discuss the dragon's position in the isles here, all the SI books point to this) and Arden Sul (PCs all possibilities self) mantled Sheogorath and nobody could remember exactly how it happened (all possibilities). At this point Jyggylag appears and basically tells you that HE is Sheogorath the Daedric prince and that he doesn't want to fight you and blah blah.

This is the part where all the previous very logical lore of the SI crumbles to pieces. Except it doesn't.

Jyggalag was really the Prince of Order (I'm kind of omitting the Daedric word here else Proweler will pounce on my head) at the time of Mundus creation (so technically he was Daedric...). BUT! But something happened. Free will happened and he became "cursed" with it (couldn't calculate anymore) and became Sheogorath. That curse is YOU. YOU the PC and every other Arden Sul beforehand. It requires a mortal aspect IN the SPHERE to change the SPHERE and that aspect is you. That's why "you"(Sheogorath with eyes) needed YOU(PC) as the "mortal champion".

When you bathe in the fountain of madness and do all that stuff you take on the original madness of the original "curse" on yourself (and obviously become bat[censored] crazy) and then apply it in mortal form to the Isles themselves (to Jyggalag).

Now the speech makes a bit more sense. When you defeated Jyggalag's Avatar (in his own realm no less, something not possible normally) he didn't "go away". It was the Isles talking to you and accepting you as the new madness medium by which it transformed back into the good old Madgod's realm. This would also explain why your staff holds everyone with Jyggy's voice (Isles voice). It's quite possible that Sheogorath always had "A" mortal Madgod in it (changed after 1000 years when exactness tried to reassert itself).

I need to digest completely what you're saying, but you have given me a slight side idea: Arden Sul is the history of you at the point you attain full mantling. When you read about Arden Sul, you are looking at the reflection of yourself as you ascend. You know how when Tiber Septim ascended, all of a sudden Talos existed, has always existed, will always exist. Same with the Numidium. Same with CoC. Arden Sul is the historical artifact of you ascending. Hmmm. Plausible, and very interesting.

And also, the mantling and crazy bits are recursive. You go insane in order to mantle Sheogorath and because you are mantling the mad god, you go insane. By the actions you commit, you mantle him, even if it's all in your head. You only take it to the half circle.

Finally, are you taking the stand that Jyggalag won't be around in the next game?

Yes and yes about the recursion. And yes, I think Jyggalag can't exist in the next game, he accepted madness of mortality and free will (you) again and got "cursed back" if you will.

Theory 3 (aka, Why You Shouldn't Listen to Ashi)
I like to play with the idea that Haskill was actually Sheogorath in disguise, who set up all the events and laughed as man-behind-the-curtain the entire time. Especially at the punch-line: You thinking that You have become Him! :ahhh:

I'd like to think that anything is possible, but that would piss all over this buff's theory now...

Uh, I'm no lore buff ( I wish) but somewhere (cant exactly remember where. Probably either UESP or the Imperial Library) it said that Jygg was cursed by the other daedric princes because they did not like him having so much power. But the way you word it make it seem as if they had no part in it.

Anyway, I've not played Shivering Isles, so perhaps I should stay silent in the matter...

http://www.gamesas.com/bgsforums/index.php?showtopic=195079

You're one step closer to achieving that lofty dream; to that teir of the tenacious so few touch: an Elder Scrolls Lore Buff!

Ah, come on, what I meant with that bit was something like "I'm not really sure about this, but..."
And that link was probably the first thing I read back when I found this forum xD

Sounds likely to me.
(but what of Dyus and Jyggalag? Were they just Sheo [censored] with your head too?)

And on the topic of Dyus and Haskill, how can a Breton and an Imperial have existed long before there even were any Bretons and Imperials? Is it just an Infernal City-style thing?

What's a fake Dunmer? Their races really don't matter. What you see in the Shivering isles is largely up to Sheog and the Champion's expectations.

The humanoid looks of Dyrus and Haskill are probably to lure us into a false sense of security through familiarity. For Sheogorath, mortals are unbound to circular blah blah blah, and have freedom of doing as they please (thus being largely unpredictable). To mirror this, Sheogorath probably fancies the form of a human, save for his daedric eyes. Also, it puts mortals in a false sense of security with familiarity.

The Sheo of Daggerfall seemed very intelligent, and rather stable. And above all: very bored - this seems like exactly the sort of thing he'd pull on you, if only for a grin or two. It'd be exceedingly ironic and hysterical, in the twisted sort of way a bored daedra prince might enjoy...from my point of view, of course, which should always be taken with a grain of salt (or perhaps several spoonfuls).

Since Morrowind's lapse in his stability of mind, I rather doubt the possibility of this; but, as I said, it's just an idea which seemed somewhat likely with the Sheo of old (Daggerfall speaking).