Your opponent has a face up Light and Darkness Dragon face up on the field.

You activate Book of Moon
LaDD negates it.
you chain Divine Wrath.

What happens and why?

Answer by Croc:

Divine wrath is spell speed 3 and LADD's eff is spell speed 2, LADD can't negate divine wrath
I activate BOM on LADD, LADD chains his eff on BOM as chain link 2 to negate it, i chain Divine Wrath as chain link 3. Now chain link resolves backwards meaning Divine Wrath negates LADD's first effect:
Quote:
When a Spell or Trap Card is activated, or the effect of an Effect Monster is activated, that activation is negated and this card loses 500 ATK and DEF.

And Divine Wrath destroys LADD and BOM resolves losing its target.
Now since LADD's Effect is mandatory:
Quote:

When this card is destroyed and sent to the Graveyard, select 1 monster in your Graveyard. Then destroy all cards you control, and Special Summon that monster.


LADD's second effect resolves after the chain.

Very well written by the way .