When Sir Lothar decapitated Medivh, Gul’dan was still linked mind-to-mind, thus causing Gul’dan to go into a coma for days. By the time he awakened, he was under custody by the forces of Orgrimm Doomhammer, who had killed Blackhand, taking his mantle as new Warchief of the Horde.
Through deception, Gul’dan offered Doomhammer a new army of Death Knights risen with necromancy from the corpses of Humans. Secretly, he had imbued the spirits of the slain Shadow Council’s orc warlocks into these human corpses.
During the Second War, Gul’dan betrayed Doomhammer taking the Twilight’s Hammer and the Stormreaver Clans from the war to travel by sea. Gul’dan used powerful magic to rise an isle from the bottom of the ocean floor.
His ships arrived to what is now known as Stormreaver Bay. His destination was the Tomb of Sargeras.
What lied within the Tomb of Sargeras would grant Gul’dan power, but instead he found death. The demons within protected the Tomb of Sargeras, and slayed Gul’dan and his followers. On the outdoors, whoever survived, was majorly slain by Doomhammer’s forces who came to avenge the betrayal. Because Gul’dan retreated his forces for this personal quest, the Horde lost the Second War.
To this day, we know Cho’gall survived the ordeal, as well as one of the Stormreavers known as Drak’Thul. Other Stormreaver hermits can be found throughout these isles too.
The next visit to the Tomb of Sargeras happened some time later, when Ner’zhul sent Teron Gorefiend through the Dark Portal to retrieve four items of power: The Eye of Dalaran, the Book of Medivh, the Skull of Gul’dan and the Scepter of Sargeras. The latter obtained from the Tomb of Sargeras.—Warcraft II: Beyond the Dark Portal (RTS) and World of Warcraft: Beyond the Dark Portal (Pocket Books)
In the Warcraft III: Frozen Throne, we also find out other Stormreavers survived the carnage. The demons bound the souls of those Blackrock, Twilight’s Hammer and Stormreaver orcs that died there, and eternally replay their battle. Though the fel enchantments binding their souls were destroyed by Maiev and her sentinels, there is no telling if the demons have restored what was undone.
Illidan and Lady Vashj came to the Tomb of Sargeras to retrieve the Eye of Sargeras, an artifact that Illidan used later in Dalaran to channel a spell aimed to shake Icecrown to its foundations in an attempt to destroy Ner’zhul the Lich King.
This earthquake is what caused the emergence of the Faceless Ones and the Forgotten One from the depths of Azjol-Nerub.
The Broken Isles is composed of four major islands and a few scattered smaller isles. It is currently occupied by the Death Hiss Naga. Goblins and their mercenaries have built settlements here lurking for any means of profit and merchantile opportunities. The Lostfin Murlocs tribe. The Makrura. Sea Giants. Hydras. Snapdragons, Dragon Turtles. Sea Turtles. All these may be found in the Broken Isles or within the temple.
Izal-Shurah is an ancient Kaldorei library. It is now a Makrura stronghold. Suramar city was formerly the home of Priestess Tyrande Whisperwind and the brothers Stormrage. Other locations in the Broken Isles, of importance, are the Boughs of Azshara which once was a fabled garden; and Arauk-Nashal.
The walls within the ancient Kaldorei temple where the Tomb of Sargeras is located, has various glyphs marked with Gul’dan’s blood. These tell the story of his last moments of life. Maiev Shadowsong abandoned her Sentinels and Naisha, a close friend, when Illidan used the Eye of Sargeras to cause an earthquake that collapsed some of the tunnels of the Tomb of Sargeras.
Whether we will find Naisha and her friends alive or as ghosts in World of Warcraft is unknown. Drak’Thul may have rescued them. Or the Druids of the Talon and Dryads may have been able to help them survive. Only time will tell.