The players had to set up the Gemini Mirror, a Divine Artifact, to create overlapping and intersecting chaotic spaces, and they couldn't let Edward's other spells destroy those fragile spaces—if the angle of the mirror was too large, it would be directly destroyed by the rays.
Ultimately, the immediate death ray that Edward's main body would release was to be diverted by multiple refractions to hit another avatar of Edward who was also present.
If hit by this ray, the player character would die instantly, ignoring any resistance, and would be unable to resurrect during the fight.
Because the ray would disappear after it killed someone, players could sacrifice a summoned creature to block the ray if the angle of the mirrors was incorrect or if there weren't enough mirrors.
Even if it was a summoned creature, after it blocked the ray and died, it could not be summoned again in that battle. In game terms, it was "permanently killed."
