Idea for a Taric rework

A Taric rework is coming up and the hype from the recent teasers reminded me of something I made a while back. I wanted to keep taric's interesting and different elements (armor stacker, on target stun, spellblade passive) and avoid his hidden power aura's and too simple gameplay. I imagine this rework could be played top or support, support with a standard tank support build and top with an ice born gauntlet, frozen heart, lucidity boots as core. Anyway here it is

Passive: 40 percent of all non physical damage Taric takes is converted into physical damage. Additionally, after using an ability his next auto attack slows by 50% for .5 seconds and deals 15% of his total armor as extra damage

Q(harden):Taric shields himself for (20/30/40/50/60) +20ap + 30% armor). This shield does not wear off and can stack with other shields from Taric. The shield can be used on allies , with half the base value (14/13/12/11/10 second cool down, 50/60/70/80/90 mana cost)

W(shatter): Taric shatters the current shield on him, dealing 1 physical damage per shield health to nearby enemies in a 350 radius and slowing them by (20/25/30/35/40) percent for 2 seconds. 9 second cool down, 30/35/40/45/50 mana

E(crystallize): Taric briefly stuns an enemy within 500 range for 1 second. If an enemy champion takes damage from shatter, the cooldown is refreshed (22/20/18/16/14 cool down, 80/85/90/95/100 mana cost)

R(imbue): passively, grants Taric 20 percent bonus armor, spitting out half of that to allies within 650 range (they gain 10 percent of Tarics bonus armor). Taric can activate this spell to slam down on the ground with his hammer, dealing (100/175/250 +40% ap +40% armor) to enemies within a 650 range and granting (25/35/45) attack speed to nearby allies for 4 seconds. The passive does not work while Tarics ult is on cool down (100/80/60 second cool down)