Thorn Fangs of Violet Poison

(This card is always treated as a "Predap" card.)
Target 1 "Starving Venom Fusion Dragon" you control; it cannot attack for the rest of this turn, also destroy as many monsters your opponent controls as possible with less ATK than that monster, then you can discard your entire hand, and if you do, inflict damage to your opponent equal to the combined original ATK of those destroyed monsters.