Balancing Ryze ..My ideas
Instead of having this 5 spells cap how about Ryze Arcane Mastery passive supercharge for 2.5sec (at all rank) and make his ult extend the duration by 2.25 / 3 / 3.75sec? This way Ryze doesnt have many resets when his ult is not active giving his ult more depth, an ult-like feeling and not just an accessory. Also changing back his ult cooldown close to how it was 75 / 60 / 45 with a 50/100/150 mana cost.
Ryze Ult Is used when his passive is stacked anyways; incorporating his ult with his passsive players wont feel like they can go through the whole game by not using Ryzes Ult.
Let me know what you think. 