Forum:Cease fire vs. Face down Light and Darkness dragon

Hello Judges:

I activated CeaseFire while having a face down Light and Darkness Dragon on the field. The dragon is then flipped up, but will it negate the damage inflicted by Cease Fire?

My understanding is Light and Darkness Dragon only negates the activation of spell, trap or monster effects, therefore it won't negate the damaging effect inflected to my opponent.

Thank you.