Taric Reworked Ultimate

To begin with, I think that Taric is a pretty good support, but his ultimate is quite bad. It provides him with some damage and the aura is powerful, but the idea of an aura based ultimate seems bad to me since it gives so much more power than it actually looks like. That way neither his allies nor his enemies fully understand his impact in a fight just like Sona's old auras. My idea is to make his ultimate kinda like Lissandra's. Rite of the Gemstones (Pretty bad name obviously) 110/90/70 seconds CD. "Taric slams his hammer on the ground, casting an ancient spell on the target champion. On self/ally cast: Crystal spikes emerge from underneath the target dealing 150/250/350 (+45% Ability Power) (+50% Max Armor) to all enemies close and briefly interrupting their movement (kinda like Quinn's Vault). The target also gains 30/55/70 Attack Damage and Ability Power, 40/65/90 Armor and Magic resist and 25%increased healing from all sources for 3/4/5 seconds. On enemy cast: Taric curses his target with an ancient spell slowing them by 40% ramping up to 90% over 2,5 seconds. After this small delay crystals start shattering in a circle (think Nautilus) around the target dealing 150/300/450 (+60% Ability Power) (+60% Max Armor) to all enemies caught in the effect and slowing them by 85% for 1 second. Affected enemies deal less damage and are dealt more damage for 1/2/3 seconds. (Didn't put numbers on this since damage reduction-amplification is hard to balance.) With this utimate Taric can really amplify his effectiveness for a short duration while also peeling for his teammates. When cast on an enemy it gives a short window to react before taking full effect providing a variety of counterplay options. However, after the delay the effect is stronger that the friendly cast. It generally gives the player more big play opportunities while creating cohessiveness in his kit and keeps the buff-debuff fashion of the aura only shorter and more impactful. The rest of his kit is pretty ok as it is since it synergises well with the Ultimate, but may need some tweaking here and there for balance reasons.

How do you like my idea? Maybe too complicated or just retarded? Don't hesitate your own crazy ideas about the fab gem knight (who desperately needs a VU!)