The CoC defeated Jyggalag in war. Either he/she's a great military genius, or he's powerful enough to defeat Jyggalag with brute force and therefore overshadows all other heroes in an overall power count(may only be physical strength, but enough of it makes comparing the CoC to any other hero ridiculous).
The recruit also fought off an entire military campaign, a military campaign that defeated a dragon and ALL Battlemages, save for the recruit, his companion, and this really old wizard.
Also, despite being insane, he/she must be mentally and emotionally stable. Try to mentally or emotionally break down a Daedric prince, especially the one who defeated Jyggalag
Being insane means you are not mentally stable! Logic fallacy there, batman. And emotional stability also tends to hit the fan when someone isn't mentally stable also.
(in both war and one on one combat), who I believe is, arguably, more powerful than even Dagon and perhaps the most intelligent of the Daedric princes, other than the person who defeated him. Dagon probably feared him.
Conjecture, without much evidence other than people feared him. You see, he was feared, because he could predict what the other princes would do to the T, not because he could blast someone to ash or crystal or what have you. Dagon, he's an extremely ancient being, who leaped through multiple kalpas before becoming Destruction. As a being whose sphere is purely about destroying things, and even he took over some other daedric princes' lands during the invasion. Plus, if the Tribunal had not been immortal, Alamenxia and Sotha Sil, during the prime of their power, would have been killed.
As for people who followed everything others told him/her, let's see if these sound familiar:
The emperor has been imprisoned and only you can save him. Go give up 10 years of your life(a little slow, isn't it?) saving him from the big bad Imperial battlemage. Ohhh, scary. Mankar Camoran could have mopped the floor with Tharn.
10 years of being all around Tamriel to the most dangerous of dungeons in all of Tamriel. Here's the thing, Tamriel is really huge. What we were given in OB and MW was extremely condensed, but time wasn't as condensed as the world. In Daggerfall, going from one little kingdom to another took at least a week. This I find to be the most accurate account of time in all games. Now, if we apply that to the EC, while being hunted down by Tharn and most likely a fugitive, it is easy to see why it took 10 years.
I only just met you, but will you go to a foreign land do some large favors for me(either Uriel's a desparate moron, Septim's Agent is an overly-obediant pawn, or both)?
It's implied that Septim's Agen didn't "just meet." Plus, if you want to do this, then we'll say the same thing about the Nerevarine and Champion of Cyrodiil, who the emperor either never met or literally JUST met. And don't you dare pull out that prophesy stuff, or else I'd smack you around with that for Septim's Agent also.
They have taken you from the Imperial City, to the east, to Morrowind. Fear not, for I am watchful. Go take orders directly for no apparent reason and help me get what I want as the spoiled brat I am.
Hello prisoner I have just met. I have been watching you for some time. Here, take this jewel that will protect all of us from going to hell, and don't you dare do anything bad with it.