I will update this to keep it up to date with changes from both the PTR and live servers. The strategy that I post is what my guild/group used to kill the boss on PTR or live. If you have a more efficient suggestion please post to let me know.
The most powerful elemental still under Deathwing's sway, Morchok once a passive guardian is now convinced that his only respite will come with Azeroth's demise. Morchok rages against the foundation of Wyrmrest Temple, Azeroth's last beacon of hope in the Hour of Twilight.
Morchok performs a massive stomp, splitting 750,000/ 3,000,000 (10/25) damage between all players within 25 yards. The two closet targets take a double share of the damage.
Morchok strikes his current target, inflicting 120% normal melee damage and reducing the target's armor by 10% for 20 sec. This effect stacks up to 10 times.
Morchok conjures an explosive crystal onto the battlefield that explodes after 12 seconds for massive shadow shadow. The explosion splits the damage between the 3/7 closest enemies and the total damage inflicted increases depending ont he distance of each player from the crystal
At 20% health, Morchok becomes furious and increases his attack speed by 30% and his damage by 20%.
The Earth Consumes You!
Morchok uses the power of the earth to draw all players to him, inflicting 5% of their total health as Physical damage. While the power of the earth draws the players to him. Morchok also summons Earth's Vengeance.
Shards of Earth's Vengeance erupt from the ground, inflicting 15000 Physical damage to nearby players within 2 yard and leaving obstacles (aka something you can LoS with).
Black Blood of the Earth
Morchok cause the Black Blood of the Earth to erupt outward from him, inflicting 5000 Nature damage and increasing Nature damage taking by 100% every second while the player stands in the blood, this effect stacks up to 20 times.
Upon reaching 90% health, Morchok tears himself in half, creating his twin, Kochrom. His twin will do the same spells Morchok performs, a few seconds after him.