Rule of 16 and not-attacks

Cleric in my game use his supernatural ability to summon light. He casts in area with magical ward, which tries to supress said light. Cleric casts with skill 14, ward was created with skill 20. Does rule of 16 apply? This isn't supernatural attack - it does not harm cleric in any way, just supress the light.

Rule of 16 and not-attacks