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.
CoC and Dovahkiin face each other. CoC stops time for everything but himself. Dovahkiin uses Become Ethereal. With this he can be invincible during the time slow down. Dovahkiin has 100% + magic resistance, so there's no effect of CoC using Mehrune's Razor on him. He just keeps freezing time and attempting with the dagger until he runs out of uses for both.
And the Dovahkiin can
1. use "Become Ethereal" for all damage to him to become void.
2. Slow Time
3. Storm Call
4. Call Dragon
5. Whirlwind Sprint
6. etc..
All of which he can use one right after another. And Dovahkiin has millions of heal, stamina and magicka and does millions of damage on every weapon, no enchantments needed on the weapons. So, CoC about to slow down time? Become Ethereal. Invincible during time slow down. CoC super fast? Slow Down Time. One shot him with a bow, slow down time even more by zooming in. Call Dragon for Odahviing to rain death upon him. Storm Call for lightning death too. Whirlwind Sprint to dodge. Just having Dragon Shouts don't make him win but they do help a helluva lot.
EDIT: THIS NEXT THING ENDS YOUR WHOLE ARGUEMENT. Taken from the page on the Staff of Sheogorath: "...and no target affected by the staff can be damaged by attacks." http://uesp.net/wiki/Shivering:Staff_of_Sheogorath
So... yeah.