First of all I suggest to increase Life Exchanges Shatter cd increasing from 1s to 2s, because Brittle can reduce its cd with too high ratio. And increase its heal from 800 to 1000 for a little compensate (it isn't enaugh of course).
And I suggest to buff it by add a new function: If you click to an enemy than you gains the 1000 heal.

So it could be used selfish too and Brittle lvl5 wouldn't be too important combinated by this talent. She also shouldn't spam Shatter too often.