Ability Idea's for a water mage

This isn't too in-depth of a champion creation post. But I was watching a Jeremy Gaming-Curious video about Taliyah, and it peaked my interest about elemental mages. I've always loved the idea of water mages, and it saddens me that there's no true water mage, other than arguably Nami, or even less-so, Fizz.

So, here's my shot at making a skill set for a water mage. For the sake of keeping it out of depth, we'll refer to this champion as Aquamancer.

Passive, Augamancy: Augamancer's abilities leave puddles of water, equal to the size of the abilities. All of Augamancer's abilities interact with bodies of water. Puddles last 20 seconds and any enemy walking over puddles is slowed by 10/20/30% (Upgrades at Levels 1, 7 and 14)

Bodies of water include puddles made from her passive, and river on summoners rift.

Q, Aqua Lash: (CD: 16/13/10/7/4) (Mana cost: 70 all ranks) (Range: 800) Augamancer can summon a thicket of water whips in an area(250 radius). Water whips strike out at up to 5 enemies in, and near the thicket, dealing 40/55/70/85/100 (30% of AP) magic damage and slowing targets hit by 35% for 1.5 seconds. (Stacks conclusively with Augamancy). If Aqua lash is cast on a body of water the radius of the thicket is increased by 100 (350 total).

So an enhanced Aqua Lash has slightly less range than a caster minion from its center.

W, Fluid Form: (CD: 3 sec at all ranks) (Mana cost: 0) (Range: Self cast) Toggled ability. Toggled off: Augamancers auto attacks will strike in a cone in front of them, dealing bonus damage to their target and everyone in the cone equal to 10/40/70/110/140 (25% of AP). While on a body of water, Augamancer gains 20/25/30/35/40% attack speed. Toggles on: Augamancer takes the form of a water elemental. While in this form, they gain 20/25/30/35/40% movement speed when running on Bodies of water or out of combat. While in water elemental form you receive 20% less damage, but cannot take any action except toggling off fluid form, and moving. Additionally you leave a puddle behind you in a trail.

E, Flood: (CD: 10 all ranks) (Mana cost: 60/65/70/75/80) (Range: 1000) Augamancer sends water crashing forward in a line (like a mini wave) knocking back enemies a set distance relative to how close they are to them, and dealing 70/110/150/190/230 (+60% of AP). If an enemy is standing on a body of water when hit by this ability, they will be briefly stunned for .5 seconds after being knock backed.

I'd like to note that the distance meter scales with proximity to Aquamancer. So someone right in his face with get knocked back equal to Aurelion Sol ult. But someone on the tip of the end of the ability might not even notice the knock back.

R, Ice Age: (CD: 100/80/60 seconds) (Mana cost: 100 all ranks) (Range: 1000) After a brief (.75) channel(that can be interrupted), Augamancer freezes all bodies of water within 1000 range of them. Enemies in bodies of water will be snared for .8/1.2/1.6 seconds and take 75/150/225 (+20% of AP) magic damage. For the next 6/8/10 seconds, Augamancer's passive, and all of their basic abilities are replaced with stronger, icier versions:

Passive, Shatter: Abilities explode at the end of their duration dealing damage equal to 50% of your total ability power around them, and slow for 20/40/60% for .5 seconds. (Increasing at levels 1/7/14)

Q, Frost Burst: After a brief delay, enemies in a circles are stunned for .6/.8/1 second and take 100/200/300 (+90% of AP) magic damage.

W, Ice Wraith Form: Toggled Toggled off: Same deal as the previous ones but a little more damage and very brief .5 second decaying slow on auto attacks, and doubled attack speed bonus Toggled on: Takes the form of an ice wraith. Same deal, but allows you to go through walls and champions, dealing some damage to enemies, severely slowing them for 4 seconds and doubling movement speed bonus. Can only be toggled for 2.5 seconds at a time, and only usable twice during ice age.

E, Heaven Fall: Giant ice spikes fall in a line, dealing 120/240/360 (+100% of AP) damage to anyone near where they fall. The ice spikes then remain as terrain for 4 seconds and slow any nearby enemies for 15/20/25%. Can only be used once during Ice Age.

I wanted this champion to feel like a zoning and a control mage, who when the time is right can go super sayain and freeze everything, and I feel like by the end of this I was pretty proud of making that come to fantasy. I hope one day we can have a classic mage for every element.

Anyway let me know what you think in the comments, don't be so fast to dislike the post and never come back again if you thought this is too strong or too weak, discuss it with me in the comments and then you can dislike it if you think I'm still wrong.