Sleip, the Eight-Legged Stallion

Hello summoners,

I've got an interesting concept for a new champion inspired by Odin's horse. I wanted to bring out more Norse mythology references to the league roster through him and also interesting mechanics. His kit is loosely inspired by the Yggdrasil and the Nine Worlds and also by the concept of stance switching champions recently.

MODEL: I was thinking of an eight-legged centaur with dark tones and fierce looks, dressed like a war horse. I also wanted him to wield a spear like Gungnir.

Passive: Will of Yggdrasil - Upon game creation, Sleip gets to choose between two passives which will influence his kit completely, making him either tanky or damage dealer.

Passive 1: Midgard, the Human Realm - Sleip chose to be the protector of people and puts on a massive armor on the model. He gets extra amor/mr per level.

Passive 2: Jotunheim, the Giants Realm - Sleip chose to be the destroyer and gets a second spear on the model. He gets extra movement speed per level.

Q - Kick: Sleip hurls his front legs to deal X amount of damage + stun ennemies for X second. This ability is also a short dash. On passive 2, it does more damage, stuns less. On passive 1, he gains a shield when the ability lands.

W - Worlds of Fire and Ice: A toggle like ability with no mana cost that either damage with fire or slow with frost for a very short time when someone attack him. Depending of the Passive he chose, the fire either does more damage, or the slow is longer.

E - Impale: An ability with medium range, Sleip impale his enemy with a spear. If he is on Passive 1, damage is doubled as he is hurling both spears. On passive 2, it gains a slow component.

R - The Gates of Agsard/Hel

Now this is the key to the concept, if Sleip chose passive 1 and, the Gates become the Gates of Asgard, for passive 2 the Gates of Hel.

Gates of Asgard: Sleip opens a door to another world, bringing out an ancient deity who shields his allies for X amount of damage/magic damage, effect applied on aoe where the doors open.

Gates of Hel: Sleip opens a door to another world, bringing out an ancient deity who torments his opponents by letting out dead spirits who fear ennemies they touch.

In both case, the opening or the gates deal damage when the doors gets out of the ground and damage in front when the doors open, slightly pushing the ennemies in front of them.

As far as game design if concerned, i don't know if this is legit possible, but this is like my personal preference for everything league has to offer ;) I know the concept implies an evolving model and shit, but man, c'mon, the badassery and the quest vs Hecarim and shit ;)