The High Priest drifts towards the player, occasionally dashing in a random direction. Additionally, bullets that travel along waves randomly appear from the walls. The High Priest has several attacks:
Surrounds himself with a ring of large bullets, fires homing skulls that burst into 6 bullets when destroyed, then fires the ring of bullets outwards.
Darkens the room, teleporting around and firing waves of projectiles from random locations.
Extends both arms and sprays rotating streams of bullets.
Extends both arms and sprays bullets randomly in all directions.
Fires wide spreads of triangular bullets.
Fires a single, fast bullet that homes in on the player.
Tips
The homing skulls can be taken down by a weapon with a high attack speed and low reload time. They can also be destroyed by simply leading them into a wall.
When the room darkens, the waves of projectiles can easily be dodged by staying in a corner and dodge rolling into the corner whenever a wave approaches.
The High Priest can be hit by Blasphemy and Bullet Bore while performing his disappearing attack and can be killed this way, unlike Cannonbalrog.