Mastery: Lightbringer beacon healer built around Holy Shock, Infusion of Light, and Holy Power spenders. What the kit brings to 2v2 Arena, the fundamentals for the role, and current video coverage.
Play near a pillar and preserve the path. Trade Freedom, Sacrifice or Protection against a specific setup instead of spending everything at the first sign of pressure.
Holy Shock creates Infusion, which is your precise answer when you have to cast under pressure. Spending it into light damage wastes the one clean global you were owed.
Use it to create your team's kill window, then position so you cannot be crowd controlled for free during their counter-go.
This is an activity playbook, not a static build claim. Start with the current class guide, then change talents and gear around your group, encounter, and rating bracket.