That's them direction ill take them eventually, fighting at the front lines casting barriers, buffs, debuffs, and other assist spells, but before I get them there id like to explore the narrative that since they're not the most experienced in combat I like the idea of having them stumble and grow into the role. Id have them start as someone who's unsure of how to best support their team, which may mean stepping onto certain healer's toes.

As for the actual healing, I'm designing it be less like filling up someone's health and more like adding armor. 

I'd say they're primarily a runecaster rather than a runestone user because in essence, I want them to be someone who specializes in creating barriers, bindings, and seals. Storywise I want to make them something like a fairy exorcist, but thematically and aesthetically like a shaman/druid who uses nature spirit/magic.