No champion should ever have mana scaling skills.

Mana-scaling skills are toxic to the game. Why? The items you build.

What often comes with mana? Defensive stats.

When a mage is rewarded for stacking defensive items because they utilize mana scaling and AP scaling, you run into a lot of problems where they're just a little too good. If you build tank with an Archangel, the second it hits Seraph, you're gaining massive amounts of mana and AP which leads to your spells chunking through two forms of scaling, and even though you only have Archangels and maybe RoA, the rest of your build is giving you so many defensive stats that it's almost impossible for you to actually die -- especially against physical damage sources. Even so, if you grab an Abyssal Mask, you're just amping your damage up further whilst also giving yourself better stats to use against mages.

In conclusion, please remove mana scaling from Ryze and my boy Kassadin. It's just... Not fair.