Bloom Diva the Melodious Choir

1 "Melodious Maestra" monster + 1 "Melodious" monster Cannot be destroyed by battle or by card effects, also you take no battle damage from attacks involving this card. If this card battles a Special Summoned monster, after damage calculation: You can inflict damage to your opponent equal to the difference between the original ATK of that opponent's monster and this card, and if you do, destroy that opponent's monster.