Idea for Ryze 2016 update

Fresh from his season 5 rework, Ryze was a top lane terror that could literally drop down tanks from full health within six seconds (see Fun Fest's [5.10] A very balanced Ryze kill montage). I think what the designers intended was for Ryze to have windows of power, like Gnar. But as someone who played a lot of Ryze, I agree with my opposing laner that it's too easy to bust out into my supercharged mode which takes about 2 seconds with CDR.

My suggestions aim for a Ryze who can once again be a hypercarry, but have very well defined spikes of power.

Arcane Mastery Ryze gains Arcane Mastery for 6 seconds every time he uses an ability, stacking up to 6 times. At 6 stacks, Ryze is engulfed in pure arcane magic, granting bonus effects on his basic abilities for 4 / 5 / 6 seconds. Additionally, Ryze gains 5 / 10 / 15 movement speed for each stack. Ryze gains no benefit from cooldown reduction.

Overload Ryze throws a charge of pure energy in a line, dealing magic damage to the first enemy it hits. MAGIC DAMAGE: 40 / 60 / 80 / 100 / 120 (+ 40% AP) (+ 4 / 5 / 6 / 7 / 8% maximum mana) BONUS: Overload deals double damage and explodes on contact, dealing its normal damage around the target (explosion radius scales with AP).

Rune Prison Ryze summons a cage of magic around a target enemy, dealing magic damage and rooting them. MAGIC DAMAGE: 60 / 85 / 110 / 135 / 160 (+ 20% AP) (+ 2% maximum mana) ROOT DURATION: .8 / 1 / 1.2 / 1.4 / 1.6 (+ .1 per 200 AP) BONUS: Roots enemies near the target for half the duration.

Spell Flux Ryze unleashes an orb upon the target enemy, dealing them magic damage and reducing their magic resistance for 5 seconds, stacking up to 5 times. After striking the target, the orb splits up into secondary orbs which hit enemies near the initial target, before bouncing back to the initial target. MAGIC DAMAGE: 36 / 52 / 68 / 84 / 100 (+ 20% AP) (+ 20% maximum mana) SECONDARY DAMAGE: 18 / 26 / 34 / 42 / 50 (+ 10% AP) (+ 1% maximum mana) MAGIC RESIST REDUCTION: 4 / 5 / 6 / 7 / 8% (+ 1% per 150 AP) BONUS: Secondary orbs can bounce up to 4 times between the initial target and nearby enemies instead of just 2 times.

Desperate Power Primal thorn magic surges through Ryze's body, releasing himself from the restrictions of normal mages, and granting vast arcane power for 3 / 4 / 5 seconds. During this time, Ryze gains a shield and ability casts reduce the cooldowns of his other abilities. COOLDOWN: 120 / 100 / 80 SPELL VAMP: 15 / 20 / 25% COOLDOWN REDUCTION: (.1 second per 1% cdr) SHIELD: 20-100 (+ 12% maximum mana) COST: 40 / 60 / 80 mana per spell cast

Ryze mains will be confused about the ability power scalings, but I made it so because the current Ryze build hardly varies. With these scalings, the player can decide whether to build mana for better sustain, or ability power for better effects on his abilities (after all, ability power should make abilities stronger :D). He's definitely a lot stronger when he has ultimate and passive up now, but it's also a great deal harder to set up for, and therefore very rewarding. I know the numbers look very off, but I just estimated how he'd scale into the new items that arrived in the Mid-Season Mage Update.

What do you think? What are your suggestions for Ryze rework in gameplay or aesthetics?