"Turning and turning in the widening gyre
The falcon cannot hear the falconer"
Maeve had stopped listening to Mab, and started listening to Nemesis.
"Things fall apart; the centre cannot hold;
Mere anarchy is loosed upon the world"
Sums up Cowl nicely, Nemesis as well.
"The blood-dimmed tide is loosed, and everywhere
The ceremony of innocence is drowned"
The Fomor stealing innocent practitioners, those with a magical bloodline.
You could find parallels throughout, but I would also add that Harry has often been referred to as a fulcrum, or "In the center", directing the turn of events.