The first time Asmodeus was subjected to this sort of attack from the combined Cherubim, he had fallen prey to it miserably.
The searing pain that he felt upon being struck by one of these beams was nothing short of debilitating and it easily disarmed him of his ability to fight back.
It was only after he was defeated and his body was violated by that bastard archangel that he learned the true secret of the combined cherubim's power.
While it seemed like the angel was a force competent in high level magical attacks; the true nature of this enemy was that it was a dangerously powerful telepath.
The numerous attacks that Asmodeus was experiencing were no more than illusions that could affect even someone made from Abaddon's own blood.
The multiple copies, the pain he was feeling, the symphony of destructive attacks- none of it was actually real.