Killswitch is a phrase, which was made by Electronica music artists, used to define a blasting event or moment. Killswitch is used for a specific moment in a song when the adrenaline reaches limits, holds your breath for a moment, and then unleashes the power of sound and atmosphere. Killswitch can be used out of music world for any such event.
"Her appearance was a killswitch of the party."
"The transition he made was a killswitch...we exploded."