The core raid ramp tool for Discipline Priest. Evangelism instantly fires a free Power Word: Radiance at 150% effectiveness and makes the next 2 casts of Power Word: Radiance instant at 40% reduced mana cost. That is effectively three Radiances off one button, which is the whole ramp.

It also activates whichever talent is picked on the Archangel / Mindbender choice node. The default raid build takes Archangel, which buffs the priest's healing and absorbs by 15% for 18 seconds. Mindbender and Shadowfiend are niche picks now, Discipline raids without a pet.

Assign to the main raid ramp of the Discipline Priest. The priest no longer needs a long ramp going into the cooldown, and needs to plant feet to spam smite for optimal healing.

With Archangel the amplified window runs 18 seconds from the cast, so put the damage inside that rather than treating Evangelism as an instant.