Annie's passive should work like new Ryze's
They both have a simmilar charging mechanic, with activation on next spell. Difference is Ryze can only hold a charge for 12 seconds instead of indevinitely.
As a Ryze player I have to say this is a much more healthy pattern, for the player and for the opponent.
Both have to pay attention to when the charge comes up and when it comes down and it doesn't result in endless stalemates, where both avoid doing anything, because the charge is up, the player to niot waste it, and the enemy to not get hit.