New Character Concept - Rook: The Elemental Guardian

So i was thinking up a new tank-type character and thought of some really cool ability combo's i think would make, not only a tank, but a FUN tank to play. Along with said ability combo's, Rook is an elemental creature that, depending on the chosen skin, would also have a different appearence to represent the specific element of said skin. For instance, his "classic" skin would be of an earthy golem. not such as Malphite, no, more humanoid looking than that, but his "classic" skin would be of the earth element. skins could range from Rook: Elemental Water to Rook: Elemental Void, so on and so forth, with unique appearances such as the "classic" earth skin being a more muscled, lumberring fellow, possibly with moss/leaves growing on him? while his "water" form would be made out of literal water type textures, making him more transparent. Just a cool thought, in reguard to that, however, his true uniqueness would come in the form of something not really seen on The Rift that well.......i guess just read this bassic description and see what i mean for yourselves, and please, feedback would be great! :)

Passive: Attuned To Nature - Rook converts 5% of his total armor into magic resistance. This effect is permanent and automatic.

Q: Fist Of Ruin - Rook plants his feet and is immobile for 1 second as his fist dramatically increases in size and throws a mighty punch at short range, charged with the power of his element, in a skillshot in the direction of your mouse dealing base magical damage and knocking back the first enemy hit. If the target hits a wall or another enemy champion, they take bonus damage and are slowed for a brief time. (costs 90 mana)

W: Nature's Call - Rook calls on the forces of nature to either convert an additional portion of his total armor into magic resistance (when cast on himself) OR convert a portion of his total magic resistance into armour for a target ally. (70 mana)

E: Summon Wall - Rook slams the ground, sending energies to a target location within a mid range radius, to summon a wall to separate himself (or an ally) from his opponent. This wall can be destroyed, but scales in strength equal to a portion of Rook's total health. SPLINTER: If Rook casts Fist Of Ruin directly on a summoned wall, the wall will splinter in the direction of the blow, dealing magical damage equal to the damage of Fist Of Ruin and the remaining health of the wall that was struck. Enemies damaged by Splinter are also slowed. Likewise, if Rook knocks an enemy into a summoned wall with Fist Of Ruin, the target enemy takes the same damage, but is stunned for a short time. (80 mana)

R: Elemental Perfect Shell - Rook taps the energies of his element to lock down a target ally in a sphere of his current element (bassed on his skin) for up to 5 seconds. That ally cannot attack or move, nor can enemies or allies move through it. Rook can, however, use Fist Of Ruin to apply SPLINTER in a large sized cone, damaging and slowing enemies, in the direction of Fist Of Ruin. If Rook casts his shell on himself, he can also use Fist Of Ruin to break free and apply SPLINTER, damaging and slowing enemies, in a smaller radius around his shell. (100 mana) - (deals base damage, plus bonus damage bassed on Rook's armour value)

So, I feel like this is a very intersting character idea, and would make for some very interesting team fighting and versitile lanining. Drop comments below and what not :)