Dark Resonator

What happens if I attack a face down Dark Resonator?

Well, I heard that if you attack face down Krebons, its effect doesn't activate and I assumed it was the same for every other card similar to Krebons, but a lot of people in advance lobby seem to disagree so I wanted the confusion to be cleared here.

Krebons
When this card is selected as an attack target, you can pay 800 Life Points to negate the attack.

Dark Resonator
Once per turn, if this card would be destroyed by battle, it is not destroyed. (Damage calculation is applied normally.)

Krebons has a trigger effect that activates during attack declaration. If Krebons is face-down at that time then his effect cannot activate.

Dark Resonator has a Continuous effect that never has to activate. His effect will work even if he is face-down when attacked.

Effect applies, it's the same like marshamallon.
Еdit:Hm neko answered first.
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