During Med'an's rescue at Ahn'Qiraj, he managed to get free and get control of Valeera to fight Cho'Gall. Later, when Meryl teleported them out, he tried to possess Med'an, but Meryl Felstorm offered himself in his place, taunting him about his abilities. The demon fell to the "trap" and possessed Meryl instead, becoming contained once again.
Since then, the dreadlord has been inside Meryl, forced to do his bidding, and sometimes helping him with his own abilities. Eventually, Meryl thought the influence of the demon too much for his relationship with the New Council of Tirisfal, so he left.
Meryl Winterstorm later went to Ahn'Qiraj to help Med'an and the New Council of Tirisfal. During the battle Meryl absorbed the fel energies that had tainted the Base of Atiesh so that Med'an could wield the greatstaff, but the influx of power gave Kathra'Natir the strength he needed the break free. His spirit immediately went after the source of Med'an's power: the council members channeling it into him from within the Twisting Nether. He effortlessly slew the blood elf Dalynnia Wrathscar and drained her magic into himself, but was ultimately defeated and chained within Meryl once more. Meryl, knowing that Kathra'Natir could break free again, exiled himself rather than place the council at risk again.
- "I am not her demon. She is my vessel! She offered herself to me willingly! And this is no child's game!"
- "Meryl Winterstorm! It's been a long time since we met!"
- "Powerful though you are, mage, you are no guardian! You have not the power to command me!"
- "I hear it too, boy, but the voice is only an echo of the past! It promises death... while I offer you life... and powers beyond redemption! Surrender to me and become greater than the gods themselves! Come! Embrace me. And be mine!"
- "You offer me a place inside you... thinking yourself powerful enough to control me? I am a dreadlord!"
- "If it is a battle of wills you want, mage... we shall see whose power is greater!"