Quote Originally Posted by Pells View Post
We are killing Hydaelyn. She's grown weaker because of the blessing she gave us, to the point that Midgardsormir had to bear the load for a little while.
He blocked off our access to the Blessing to test us, rather than taking her place.

Her being weakened due to the Blessing is more from things like protecting us against the Ultima attack, rather than us being a constant drain just existing (which is the case with primals).