Make Taric's ulti more similar to Galio's w
One of the reason I don't play taric anymore is because his ulti is somewhat clunky to use. With the high damage/burst in the current meta, you don't always survive long enough for taric's ulti to become usefull. It is also very easy for the enemy to play around the delayed effect of the ulti since it has a 2,5 second activation time. It also has a very high cooldown for an ultimate that is relatively difficult to utilize.
It would be better if his ulti works similar to galios w, where he has to charge up his ulti from 0 to 2,5 seconds. If he releases the charge, his ulti will activate and the duration of immunity will depend on how long he has charged his ulti. Ex 0,5 second charge -> 0,5 second immunity.
This is good vs high burst target like rengar or an incoming jinx ulti, where you don't want a long duration of immunity, but rather a fast activation of it.