Modern gaming apologist: I once tasted diarrhea so shit is fine.
"People who alter or destroy works of art and our cultural heritage for profit or as an excercise of power, are barbarians" - George Lucas 1988
the bold made me realize this isn't going to be at all accurate when assembling a decent dragonborn... let alone someone stacking anything other than health if health is going to be an issue. not including the magic immune possibility no mention of perk stacking for enchants (chaos can triple and quadruple dip multiple % modifiers on it's damage)....
chaos is what. 1.5 mag for each element? at 100 that's something like 150 per, but you can go higher with teh destruction and enchanting perks. pair it with, say, fear and you can eek out even more through illusion perks.
no mention of 30% spell absorption or possible 80% with right stone sign (or 100%+ if you know how).
nice try overall but not thought out enough.
Looking at this from a lore perspective (the only logical way to tackle it instead of basing the fight off a bunch of meaningless numbers and game mechanics) Lore wise a practiced user of the thu'um (tongue) has the ability to shout apart entire castle walls. In fact many nordic generals, Jarl and Thanes in the times of old used it very openly and would hardly ever need actual siege weaponry as their voices could level cities. The greybeards (not all but some) have live a mute life as they become so atuned to the thu'um that just speaking normally can cause earthquakes, avalanches or shake the entirety of Skyrim.
Dragonborn are dragons in all sense of the word, minus physical appearance/body and can do anything a dragon can minus physical limitations (like flying). All the aedra have different aspects. Akatosh, Auriel, Alduin, Alkosh, Aka-Tusk, Tosh Raka, Ruptga, AKHAT, All dragons, including a dragonborn are all shards/fragments/pieces of the AKA oversoul (some just bigger/more powerful pieces than others). Imagine each god as a body (in this case the body is Time - AKA) , with each cultural/racial aspect as one limb created by faith, stretching outward, representing one trait or "dominion" of their sphere; Auriel is the beginning of Time, Akatosh is all of time, Alkosh is the maintenance of time, Alduin is its end etc etc. They are all one, but also separate and independent. They fight amongst themselves, they make love, they merge and split and multiply all according to the beliefs of mortals.
Almost all Dragonborn are destined to be legendary figures, heroes or leaders. As they are literally living fragments of time/AKA/Akatosh itself in a mortal shell. The dragonborn in Skyrim has consumed the souls of countless dozens of dragons by the time he faces Alduin. The more dragons 'slain' the stronger he becomes. The shard/piece of time/AKA that is the dragonborn essentially consumes the shard of AKA that the dragon is, in a sense making the peice/shard of Aka the dragonborn is larger and in turn more powerful. The Dragonborn becomes so powerful, he is an aspect of time almost as strong as Alduin (though not quite as he still needs the assistance of the spirits of 3 legendary, albeit regular nord, tongues). Then you take into account all the dragons that either fall to the Dragonborn after Alduin and then Miraak who was a millennia old Dragonborn who over the centuries consumed hundreds of Dragon souls himself and his soul/power is then taken by the Dragonborn.
So ya prophesied legendary heroe that is a dragon/piece of a god/time itself in a human body > Random Gronn who killed wow dragons a lot
actually, when the greybeards speak, it shakes all of tamriel. storms appear as well.
and they're not even as strong as the first tongues.... gormlaith, feldiir, and hakon. the dragonborn is stronger than the tongues, stronger than miraak, and stronger than a god/demi-god that eats the world when it's time for it to end.
this is insane rapestomp in favor of the dragonborn. the dragonborn can also just rip gruul's soul out, due to the shout he learns from durnehvir.
If he can keep dodging and using shouts the dragonborn would probably win. Because fall dmg exists in skyrim if Gruul actually landed a hit the dragonborn would go and flying and end up goo.
What version of Gruul are we talking about here? Outlands or AU Dreanor Gruul?
Shath'mag vwyq shu et'agthu, Shath'mag sshk ye! Krz'ek fhn'z agash zz maqdahl or'kaaxth'ma amqa!
The Black Empire once ruled this pitiful world, and it will do so again! Your pitiful kind will know only despair and sorrow for a hundred thousand millennia to come!
Avatar drawn by Sir Meo