“Slay him, his demon whispered. Slay Illidan and achieve eternal glory. Slay the Betrayer and become a dark god.”
"Vandel felt the temptation rise within him. If he slaughtered Illidan, he would be welcomed by his demonic kindred. He could put his mortality behind him forever, live untroubled by fear and regret. He could bury all traces of guilt about failing his family, all remorse, any semblance of kinship with these weak, frail creatures of flesh and blood. He could transcend what he was, join the Burning Legion, and become a conqueror, cleansing the universe of the foul disease of life. He could help bring creation crashing down so that a new universe could be born, one shaped in his image, by his desires.
"For a moment, he wavered. He listened to the voice of his inner demon and realized that it was his own. His soul had been tainted when he devoured the felhound. It had absorbed the demon’s evil and been twisted. There was really no other demon than himself.
"To give in to the voice of temptation would be to forswear his quest for vengeance and break faith with his dead wife and child.
"He did not want to kill Illidan. He wanted to kill the things that had made Illidan into what he was. He understood now as he never had before what the Betrayer stood for, because of what he stood against. For all his gigantic flaws, Illidan was the only being who really grasped what they fought, and he was prepared to do whatever it took to end the threat. He might well be mad. His schemes might well be doomed to failure. But he was better than the alternative.
“The demons of the Legion advanced toward the ridge. It was time to do battle with the real enemy.”