Nevermind Paralyze, Eregos has no way to dispell Ozruk's Spell Reflect. So, the fight would go like this:


Ozruk and Eregos enter the arena, and eye each other.

"This construct of stone is my opponent? Ha! The magic that binds you will bend to my will!"

"Magic...? I am no Magic construct. Come! Break yourself upon my body!!"

Ozruk charges in as Eregos begins hurling a number of Arcane Barrages, managing to get 3 off before Ozruk can close the distance. Once in melee range, Ozruk notices that Eregos is still spamming his Arcane Barrage, so he puts up his Spell Reflect. The reflection of his own spell momentarily stuns Eregos, and gives Ozruk a chance to use Ground Slam, which at point-blank range hits Eregos HARD.

Once he recovers, Eregos shifts to the Astral Plane, and summons his Planar Anomalies. While Ozruk is a little confused at why he can no longer hit Eregos, the Anomalies do hurt, so Ozruk is forced to flee, during which time, his Spell Reflect wears off. With the Planar Shift finished, Eregos once again begins blasting Ozruk, but also summons a number of Whelps to aid him.

As his Spell Reflect is still on cooldown, Ozruk decides to use his Paralyze/Shatter combo, which allows him to both close the distance to Eregos, and kill off the annoying Whelps.

With the death of his Whelps, Eregos goes into a Frenzied Assault, and justs pelts Ozruk with Arcane magic; however, Ozruk's Spell Reflect has just come off cooldown, and due to Eregos' reduced cast time, is able to Reflect over 5 fully charged blasts right back at Eregos, severly hurting him, and leaving him wide open to a Ground Slam, which finishes the fight.

"Hehehe... Your Magic has failed you dragon. This is the World's Heart, you should have stayed in Northrend..."

As Eregos falls, his arcane energies create a small portal a week into the future. As Ozruk leaves the arena, we see a glimmer of two humans making s'mores over a lightly burnt piece of cardboard.

Ozruk and Whitemane have eye contact for a moment, both knowing that their future battle will be fierce.

@Saf:
I am not sure you are taking the character of these opponents into consideration. One is a member of the Blue Dragonflight: One of the most intelligent and learned factions in this game. He may fall for the Elementium Bulwark once, but since Ozruk calls it out every time he casts it, it won't be hard to avoid after the first time.

"Blue dragons are not cruel beasts, preferring a quick kill for enemies and prey alike. They often use their abilities and spells from afar... They are excellent tacticians and attempt to damage or disable any opposing spellcasters before they commit to a physical attack. Blue dragons prefer to fight from the air, using spells and breath weapons to their fullest." -via Wowpedia

Now normally that would mean paralyze+flying = fall. However certain rules prohibit flying, so Eregos will just keep his distance and be paralyzed at range. Oz always follows his paralyze immediately with a shatter (before closing any distance), making it useless against ranged foe (technically the whelps will all be ranged too). He will take the damage when the debuff wears off, which is hefty, but not devastating to a boss.

Ground Smash can also be sidestepped thanks to its 3 sec cast. So again, he will only get one off before Eregos learns how to out maneuver it.

Looking at Ozruk, we see he is a rock, which is as dumb as...a rock:
"Ozruk has served as Stonecore's guardian since Deepholm's creation. It is unknown why Ozruk has remained in the Stonecore, but it has become apparent that the guardian now believes that anyone opposed to Deathwing is a threat to Deepholm, and should therefore be destroyed." -Wowpedia

So he now aligns himself with Deathwing despite his shattering of the World Pillar which endangered the World's Heart to begin with. Ozruk is clearly the dullest in a series of very dull tools. As such I imagine he will just blindly go through his rotation without strategy, which is very easy to plan around.