V Rising 1.1 boss guide for Azariel the Sunbringer, covering location, key attacks, Normal and Brutal Mode strategy, rewards and progression.

Azariel the Sunbringer combines the difficulty of reaching heavily guarded Brighthaven with a cathedral battle built around Holy damage, summoned aides and persistent spell hazards. Preparation begins before the arena: bring Holy Resistance and avoid wasting your resources on unnecessary patrol fights.
During the encounter, the biggest improvement is learning which summoned objects and enemies must die immediately. If you spend the whole fight tunnelling Azariel while the room fills with Holy pressure, later projectile waves become much harder than they need to be.