This is meant to provide a fast cool down of abilities, at level 20 with nexus frenzy you can use your heoric and heal your entire team from another lane and do it again in about 10 seconds. I find that I can also help burst down anyone in a team fight.

I have found that battle momentum allows me to heal more with the Q, and overflowing light adds more healing on top of lowering the cooldown of the heroic. The healing ward provides a lot of heal of time for the entire team which is great to play down during a team fight or an objective