Well, technically you don't have to go to Whiterun. According to lore, yes, heroes will do the MQ.

when you click on them you read them

Fixed that for you.

If you don't go, the event never happens. In this case, dragons will never come.

Well that is just too easy. Shouts or not, COC has vastly superior gear. Madness ore armor is superior to daedric, and roughly equivalent to dragon bone. However, Madness ore swords are superior to daedric swords, which are the best in Skyrim. The enchanting system in Oblivion allows you to create weapons and armor that are infinitely more powerful, including swords that stack weakness to and damage to the point that they can kill anything in three hits and armor that makes you permanently invisible. In addition, my COC was a powerful vampire (something that doesn't exist in Skyrim) with a huge arsenal of daedric artifacts and weapons, including Umbra, which is stronger than any sword in Skyrim, and the Escutcheon of Chorrol, which is the most powerful shield ever seen an an ES game. In addition, if you had a mage COC, offensive spells in Oblivion are MUCH more effective. Finally, next to dragon shouts, the COC has access to a myriad of greater power spells, even if he is not a mage, which include all of the doom stones (which provide the most powerful buffs available in either game), the powers gained from rebuilding the gate keeper, and even the Staff of Sheogorrath. I mean face it, the Dovakhiin cannot defeat an immortal daedric prince. In addition, the Dovakhiin is a hunter, built to destroy dragons. His abilities are tailored to facing dragons, not other great heroes, and certainly not Daedric Princes.

Are you forgetting you CANNOT enhance gear in Oblivion? In Skyrim WITHOUT exploits you can make weapons that do HUDNREDS of damage easily. Even thousands. In Oblivion the most damage you can get on a weapon is like 35 which is a Bound Claymore. Granted the games are scaled more around this in Oblivion.

Anyways, THIS FIGHT IS NOT BASED ON GAMEPLAY MECHANICS. It is based on lore. Gods CAN be killed temporarily. The Daedra comeback through the waters of Oblivion, I don't know what the Aedra do. Not being able to harm Sanguine in game is a gameplay mechanic. Sheogorath in the Shivering ilses though might as well be invincible. He could change the laws of physics and whatnot there if he wanted to.

agreed

Try stacking weakness to magic, weakness to fire, weakness to frost, weakness to shock, shock damage, fire damage, and frost damage with a 5 second duration. 3 hits and any opponent is dead. Alternatively, use demoralize to make ANY enemy flee, rendering them unable to counter any attacks. And then there is invisible armor which wins the battle in and of itself. CoC's gear is superior, and the OP specifies with any gear available. According to lore, CoC is a god, Dovakhiin is a dragon killer.

1. Necromage vampires get 25% boost to absorption.

2. I forgot that arrows can bypass reflect damage in both Oblivion and Skyrim rules. The Dovahkiin can deal upwards of 20K damage per arrow and that is the lower end without abusing Potions like nerevarine. COC has virtually no damage if spells don't work for him.

3. Mehrunes Dagger is interesting. It won't work against Nerevarine who is flying, for sure. We cannot tell if it will actually work against a 100% Magic Absorption Dovahkiin because almost every darn thing is considered magic.

4. Staff of Sheogorath can freeze time. But he can't damage anyone during that time. So it does not really help much.

5. Conclusion. COC has very low damage so he isn't likely to be able to kill either of the two who can hack themselves to a million health. Nerevarine have 32-bit health (and damage?), Dovahkiin has 64-bit health and damage so ultimately Dovahkiin will win.

Did you not read the post at all? He/she said "THIS FIGHT IS NOT BASED ON GAMEPLAY MECHANICS!"

The Dhovakin would win because he/she has superior fighting mechanics. BTW it's really amusing to see this has turned into a kindergarten-style my-dad-can-beat-up-your-dad argument. And with such ferocity too!

okay, considering half the people are talkin gameplay, and others are talking lore i changed the OP, now as long as your arguement makes any kind of sense its valid

"Greetings fellow prisoners,
in your opinion, who would win in a fight? the CoC vs Dovahkiin!
you can decide said combat useing either gameplay mechanics or lore, as long as ur arguement makes sense
I Personally have to go with the CoC, he has Dusk/Dawnfang, has access to the crusaders Relics, not to mention the Imperial Dragon Armor.
so who do think would win such a fight?" He specifically says you CAN consider gameplay mechanics. What in the world are you talking about?

In any case, if we are only referring to lore and not gameplay mechanics (which make CoC stronger), CoC still wins because daedric artifacts are part of lore and CoC controls much more powerful daedric artifacts, such as the Staff of Sheogorrath, Umbra, Goldbrand, the better version of the Skull of Corruption which essentially changes the battle to the CoC AND Dovakhiin against Dovakhiin, which once again decides the battle not even considering the CoC is also a Daedric Prince. Throw in Volendrug, which paralyzes opponents in Oblivion, allowing you the mother of all stunlocks, and the Escutcheon of Chorrol, which reflects any damage Dovakhiin might do back upon him, and there is no contest., especially when dragon shouts are no better than the CoC's greater powers.

That post. The poster I quoted quoted this post but seemed to fail to read the part i pointed out

I refer to what I said before:

Nerevarine would wipe the floor with both of them

Agreed, and yet at the same time I can understand it because I can't help but feel my jaw drop when there's all these people saying a guy that can go "AAAAAAAAAAAAAAAAAAAAH" is gonna kick the ass of someone who CAN STOP MOTHER [censored] TIME ITSELF and has obtained the power of a God. Not just any god, but of -THE- daedric god whose power the others feared the most, so they put a curse on him.

Stop time for what, 10 seconds? With limited use? And he gained Sheogorath's powers, not Jyggalag's. Jyggalag was the one they feared. And the powers gained only worked in Shivering Isles, and even then weren't that great.

This is hard battle. I can't go immediately with CoC because he never became Sheogorath - one who did it was another character.
These are the ones in the fight:

Champion of Cyrodiil_____________Dovahkiin
Altmer Spellsword_______________Nord Warrior
Full ebony armor________________Dragon Scale armor, instead of helm enchanted circlet
Shortsword and shield____________Two-Handed-Axe with Decapitation perk
Destructive magic_______________Dragonshouts

Battle begins and Dovahkiin takes fireball on his face. He still runs towards the CoC who raises his shield. Dovahkiin shouts Disarm and CoC's shield and tiny sword flies away. Then he raises his axe before CoC has time to react and decapitates him. High Elven head is lying on the ground and Dovahkiin has won the battle.

You're scoffing at 10 seconds? Per cast?

Kk picture this.
CoC and Dovahkiin face each other. CoC stops time for everything but himself. With this he can dodge any arrow and work his way around behind Dovahkiin.
Mehrunes' Razor. Dovahkiin has piss poor magic resistance, so there's no risk of using it on him. The Dovahkiin CANNOT use Mehrunes' Razor on CoC because there's a risk it'd reflect and kill himself. He just keeps freezing time and attempting with the dagger until it works.

Besides this, what Dovahkiin's capabilities are to smithing is like CoC's capabilities to magic. CoC can buff his speed stat to a ridiculous degree; I've played Oblivion before with a buffed enough speed stat that the world wasn't loading fast enough. The exact same can be done for magic damage debuffs as well. Freeze-time, debuff number one, debuff number two, etc etc until a single shot will drop him.

So we're talking about Dovahkiin trying to hit a permanently invisible fast-as-hell (in every direction; can also jump high as hell thanks to Acrobatics) target that reflects all magic damage and can stop time....with a bow shot. And the MOMENT time is stopped, CoC has him exactly where he wants him and Dovahkiin is completely at his mercy.

To tell you the truth, I am often amazed and puzzled by the popularity of many threads.

Well I guess what I was trying to say was...

If someone says "SPIDERMAN VS BATMAN WHO WULD WIN" then yeah wtf who gives a damn.
This one though? I can see why it's carried on this long because personally, logical fallacies annoy the piss out of me.
Every time I hear:

"CoC can stop time itself."
"Ya but Dovahkiin can shout so obvsly he wins."

Then yeah, sorta makes me wanna speak up and say "tf are you drinking."

I just remembered one attack that the Dovahkiin can use to win for sure. This will finally put an end to the whole thread.

Kill animation. It bypasses most normal defense mechanisms as long as your damage is greater than his health. The attack is a scripted death so there is no reflect damage nor physical immunity that can save COC. As mentioned, Dovahkiin can have health and damage in hundreds of millions. So COC + Mehrunes (chance based and assuming it can work on players) isn't going to work quite as well as Dovahkiin + Kill animation which has a much bigger range if I might add.

As for Nerevarine, without an instant kill mechanism, he is just a pest. A flying gnat that can keep raining fireballs that deal no damage. Up until Dovahkiin puts a 42565356544 damage arrow in him.

Hmm let's look at it pre-DLC, since we don't even know what the Dragonborn is gonna do. Not fair to compare someone who has only completed half of his journey to someone that's finished and attained godhood.

A dragon-killer vs. a demon killer is basically what it comes down to.