Mastery: Lightbringer beacon healer built around Holy Shock, Infusion of Light, and Holy Power spenders. What the kit brings to Raid, the fundamentals for the role, and current video coverage.
Its critical strikes create Infusion of Light, which turns your next Holy Light or Flash of Light into a deliberate answer rather than a panic cast.
Spend Holy Power on the right Word of Glory or Light of Dawn target pattern, then use Infusion to choose between fast single-target recovery and an efficient larger heal.
Avenging Wrath, Divine Toll, Aura Mastery and Lay on Hands go where the fight needs them. Do not overlap them just because several players happen to be low at once.
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.