Before Deathwing arrived in the Blade's Edge Mountains, that vast, twisted land had only one master.
Gruul, the mightiest gronn, was said to be the first gronn born in this world. He had naturally received the earth's blessing and wielded the Earthen Power of Draenor World. The innate brute strength of the gronn also made him unstoppable. Even a being like Deathwing could gain no advantage against him.
Of course, that was because Deathwing carried Azeroth's Earthen Power. In Draenor World, its effects were diminished by at least two-thirds. Just as Deathwing could easily shatter the World Pillar on Azeroth and trigger a Cataclysm that reshaped 60% of the planet's surface, Gruul could do the same on Draenor.
Such a monster should have been impossible to defeat, but Draenor World had already shattered, greatly weakening the Earthen Power he wielded.
Even so, he remained the most terrifying creature in all the Blade's Edge Mountains.
Besides Gruul, other gronn were scattered throughout Draenor. The strongest among them were called the Sons of Gruul. That did not mean Gruul had fathered them, of course. It was merely a title signifying submission. They shared no blood ties, but as the strongest fighters under Gruul's command, they meant almost as much to him as sons would.
Without these Sons of Gruul, Gruul would have faced the awkward predicament of being surrounded during the earlier battle against the black dragons. Thus, powerful as he was, the Sons of Gruul remained indispensable.
There had once been numerous Sons of Gruul, but after the Black Dragon War, only seven powerful Sons of Gruul remained. Scattered throughout the Blade's Edge Mountains, Terokkar Forest, and Nagrand, they each ruled the ogre tribes in those regions. Remember, the gronn were the ogres' masters.
That was actually a rather unfunny joke,