If you can design one skill into the game on healers, what would it be?

Personally, I'd like to see something like Thresh's lantern from League of legends put into healers as a role skill.

Thresh's Lantern provides dual-purpose to the party by:

1. Throws a lantern at a specific range and applies a shield to you and any players who walk in the lantern's radius / Applies a shield if players are in the lantern's radius when snapshotted -- effectively a ranged aoe shield. Basically useful to help keep people alive in general, but nothing as powerful as a 30y radius shield. You can think of this as a shield version of Cure III.

2. Allow players to quickly dash towards the healer by clicking on the lantern as the other end of the lantern is tethered to the healer.

The latter half of the skill makes it entirely the party member's choice if and/or when they want to quickly move towards the healer's location. The lantern is designed to give an additional choice. It's a non-intrusive skill designed to save the party and allows the healer to interact with mechanics with safe spots better, but it can also just be used as an oGCD shield if they don't feel the lifeline is necessary.