Forum:Herald of Perfection vs Monster that cannot be destroyed by battle

1st: If a monster that cannot be destroyed by battle is successfully attacked can Herald of Perfection use his negating effect to destroy it, and if not why?

2nd: Assuming he cannot,if a monster successfully attacked Reptilianne Naga could Herald of Perfection use his effect to negate the reducing atk to 0 effect, and if so when?

Any help in resolving these questions would be appreciated.