The books is better, in the show they whitewashed her during the first seasons but then they realized that in order to do her (probable) original ending they'd need major changes.

So they did them. In a single episode. A change that should have been foreshadowed seasons in advance. Sure, the destruction had been foreshadowed, but not her incredibly sudden change.

Also, just because some prophecy says X will happen doesn't mean the lead up to that end will be well done by the author or showrunner.