AOJ and face down monster

WHen AOJ attacks a face up non dark monster, we noe that without damage calculation, the monster it battles will be destroyed.

But AOJ now attacks a defense face down position monster, how will u noe its not a dark until damage step when the face down monster is flipped?

So its effect will not activate , rite?

the monster will flipped, if non-dark straight destroy... same like drillroid.. so effect got activate

i tink wont destroy cos AOJ say skipp damage.
but when the face down turn face up is damage step liao, so how to skip.
tats wat i saw many players have done oso so i wann clarify oso...

no flip up, it just dies