Once on Draenor, the black dragons settled into the Blade's Edge Mountains. They were not there long before they were attacked by Gruul, his offspring, and a small group of Alliance Expedition fighters. The eggs were destroyed and Deathwing was forced to flee from battle, followed immediately by Sabellian.
Deathwing managed to return to Azeroth, but Sabellian remained behind on Draenor — now Outland. He is a fierce enemy of Gruul the Dragonkiller and Gruul's seven sons, and hates them deeply for killing Sabellian's own people and children.
"My loathing of interruptions is overshadowed only by my hatred of Gruul the Dragonkiller and his seven sons!"
Showdown
Showdown between Goc and Sabellian
Goc yells: Who dares rouse Goc from his restful slumber? Baron Sablemane yells: It's only right that you know the name of the one who will take your life. Goc yells: Your name is as insignificant to me as the names of the thousands who have died under the might of Goc. Baron Sablemane yells: Baron Sablemane. It will be on your lips as you gasp your final breath. Baron Sablemane yells: Let us begin. Battle begins. Baron Sablemane yells: Your father destroyed my children and left their bodies impaled upon the rocky blades at Dragons' End. For this, you will die! Enough of this farce. Prepare to face my full wrath! Baron Sablemane begins emanating immense power. Baron Sablemane transforms into Sabellian and proceeds to kill Goc.
Speculation
This article or section includes speculation, observations or opinions possibly supported by lore or by Blizzard officials. It should not be taken as representing official lore.
It is also possible that Sabellian has something to do with the Black Dragonflights attack on Azshara due to the fact that the area now is called Sable Ridge. This can be supported with the fact that the drakes soaring over the area are called Sable Drakes and the area itself is called Sable Ridge.
This area however is later wiped out with the help of the blue Wyrm, Azuregos.