During the Second War, Oranaok served in the Old Horde under the leadership of Orgrim Doomhammer as a mage. Later, when the Third War erupted, Oranaok joined the Horde and became a warlock - having remembered the magics he learned when he formerly served the Legion. Under the command of the Warchief Thrall, Oranaok fought against the Legion, and participated in the Battle of Mount Hyjal, and witnessed the death of the demon lord, Archimonde.
Eventually, during the War on Outland, Oranaok was put in charge of facing off against the Illidari demon hunters under Illidan Stormrage's command. Oranaok lead several warlocks to face off against the Illidari, however most of the time their powers were equal to each other, as both used demonic powers.
During the Northrend Campaign, Oranaok was stationed on Orgrim's Hammer, flying over Icecrown for a large amount of the war. Later, Oranaok witnessed the second death of Dranosh Saurfang, and eventually helped bring down the Lich King Arthas Menethil. Afterwards, Oranaok became a Grand Warlock in the Horde.
Upon the events of the Shattering, Oranaok was sent with several other warlocks in the Horde to spy on the Alliance, whereas their city was damaged by the Cataclysm. Eventually Deathwing was slain, and the Horde was finally at a small peace, except for the fact that the new warchief, Garrosh Hellscream, continued to launch war upon the Alliance. The war took them to Pandaria, where the warchief eventually corrupted the Vale of Eternal Blossoms. Oranaok, seeing great power in demonic magics and whatnot, was surprised at the warchief's actions, and decided to join the Darkspear Revolution against Garrosh.
Oranaok later traveled to past Draenor and helped establish Frostwall, and after that had no other participation in the war against the Iron Horde. However, later when word of the Burning Legion assaulting Draenor reached Oranaok, he and his warlocks traveled to Draenor and participated in the Assault on Tanaan Jungle, and the taking down of Archimonde.
Note for the future: Oranaok will play a major role in the Legion events.