Blood of Mannoroth

The blood of Mannoroth, the vile fluid that ran through the veins of the Destructor, was used to corrupt the orcish race and bind them to the will of Kil'jaeden. Prior to the opening of the Dark Portal, Mannoroth was summoned to Draenor by Kil'jaeden, who instructed the orc warlock Gul'dan to spill the Destructor's blood into the empty meditation pool of the Temple of Karabor. Sometime later, assembled at the Throne of Kil'jaeden, the vast majority of the orcish race - the first being Grom Hellscream and his Warsong Clan - drank the burning blood, and became minions of the Burning Legion. Only a select few, most notably Durotan and his Frostwolf Clan, refused to drink. After the Horde was defeated and rounded up into internment camps, the orcs began to suffer serious withdrawals and sink into lethargy, or succumb to demon-crazed madness. Hellscream resisted the maddening bloodlust and paralyzing lethargy that was consuming his race for many years...until the Destructor's blood flowed again.

Hunted by the forest demigod Cenarius and the night elves due to their lumber operations in Ashenvale, Hellscream and his Warsongs came upon a corrupred fountain of life, the Chaos Well. Hellscream's witch doctors, who had sensed the power of the fountain, now warned him that the fountain was cursed, but the Warsong chieftain and his forces drank from the corrupted fountain anyway...and thus became the slaves of Mannoroth once more. Mannoroth - at the advice of the Dreadlord master of the Scourge, Tichondrius - had spilled his blood into the fountain, knowing that Hellscream's warriors would eventually find it. This would have the effect of not only returning the Warsongs to their blood-crazed past, but also dealing with an old foe: Cenarius himself. After Mannoroth was destroyed, the effects of his blood began to fade, and eventually disappear entirely.