Illidan still harbored a special feeling for Maiev, and Maiev felt the same way about Illidan.
The details of their past could no longer be verified, but one thing was certain: Maiev's feelings for Illidan were definitely not hatred. There was no doubt about that.
Ten thousand years ago, during the War of the Ancients, the heavens collapsed and the earth split apart. After surviving that desperate ordeal, Illidan attempted to recreate a small Well of Eternity. But his actions were undoubtedly a challenge to the fledgling druid regime, a challenge to the authority of his brother, Malfurion, and a provocation against the Cenarion Circle.
After the great war with the demons, all blame fell on Azshara, the Kaldorei queen at the time, and the druids regarded the Well of Eternity as the very root of evil.
After Illidan ignored their warnings and created a new Well of Eternity, Jarod, the Night Elves' highlord at the time, appeared, hoping to stop him.
But Illidan refused to heed this "advice" and injured Jarod instead, sending Maiev into a rage. What happened afterward was known throughout Azeroth: Illidan was found guilty and sentenced to life imprisonment, with Maiev personally guarding him, until ten thousand years later, when Tyrande entered the prison herself, killed a great many Watchers, and freed Illidan.
This made it quite clear that Maiev did not hate Illidan. If she had simply hated him, he would never have survived to this day.
It was all too easy for a prisoner to die in an "accident." Besides, everyone guarding Illidan's prison belonged to the Watchers. No one would have stopped Maiev from making a move against him. And had she lacked opportunities to kill him? If Maiev truly had a blood feud with Illidan, he would have died long ago.