The Sacred
The Sacred is a Boss added by The Ascent of Isaac Godmode that can be found in 
Cathedral.
It is the alternative final boss of the floor, having a 50% chance to replace 
Isaac.
Behavior
Phase 1
The Sacred is actually 3 different entities with 3 different colours (blue, red, yellow) sharing the same health pool. During the fight, they constantly barrage the left and right side of the room with 
Crack the Sky beams. During this phase, each boss will attack one at a time. Isaac can only damage the attacking bosses while the others will turn semi-transparent and cannot be damaged. The Sacred will always attack in the same order:
- The Yellow one appears and shoots one homing explosive projectile.
- The Red one appears and dashes towards Isaac, then bounces around the room, constantly shooting homing projectiles behind it.
- The Blue one appears, places itself at the center of the room, and shoots from the sky 3 rings of projectiles, each ring increasing in size and decreasing in speed.
- All the bosses appear at once, rotate around the room, and shoot a burst of projectiles in front of them while the Crack the Sky beams stop.
Phase 2
After The Sacred has its hp reduced to 50%, 
Revelation beams are regularly fired towards Isaac from one of the upper corners of the room. The beams' fire rate increases the less hp The Sacred have left.
Video Showcase
Trivia
- Each boss represents one of the Three Primes of Alchemy.