What if there was a shield that was not instant, but grew in strength the longer it was channeled?

So a shield which grows in strength the longer you channel it on yourself or your ally, but needs channeling which can be interrupted.

So instead of offering someone an instant bonus 200 health in shield, you can channel for 2-4 seconds to give someone a 600 shield, which starts out at a 50 health shield, but then grows exponentially the longer it is channeled on an ally. You can walk around during the channel like , but it is interrupted by hard CC, instead of just damage.

This means in order to protect your ally you need to be able to dodge CC so that you can keep the channel up so that you can keep your ally alive.