Actually, the current Warchief of the Horde should be Saar.
When all the Orcs had been freed from the curse of Tainted Blood, which was really a process that was much more difficult than one could imagine, the Warchief Saar had already seen too many orc heroes fall under the control of The Hand of Fate. Now, it looked like Kargath Bladefist would also meet the same gloomy end.
Kargath Bladefist was currently daydreaming in the Shattered Halls in Hellfire Citadel. It was declared that he was the one and only 'Warchief' of the Horde. With the help of such fierce and bloodthirsty forces, he wouldn't rest until the Thrallmar barbarians had been flattened.