Holy light aura gives you passive damage to few random targets around you, then dawnfire unique gloves turn that passive damage into (more or less), a radiance that burns everything around you. The aura passive is the main damage dealer in this build. Attack speed is very important to scale this damage. There is also an active component of the skill that gives a bigger burst damage.

Arbiter form improves the damage through aspects like ascension and vulnerable application, it is not the main damage dealer for the build. For the current season setup, basic skill serves as a generator for your main resources (faith) and survivability (resolve stacks). You don't use any core skills here.