Ron, Molly and Dumbledore will resort to putting love potions in Emily's food and drinks.
Ron has shown genuine hatred at his repeated failures in acquiring the Potter fortune, with the fake-out book being unusable. It is theorized that Ron will go to his mother and Dumbledore and try to drug Emily into loving him, as being himself has offered no benefit.
Dumbledore will lose his seat in the ICW should Harry or Emily's name come out of the Goblet of Fire while Barty Jr. and Barty Sr. are arrested.
Harry will call up Steve to investigate how his or his twin sister's name got into the Goblet of Fire, which would cause Dumbledore to lose his seat in the ICW, as well as capture Barty Junior earlier than canon. It would also result in the arrest of Crouch Sr.
Dumbledore will eventually go too far and try to kill Harry.
Given how much he hates the boy for not only going up against his so-called perfect utopia, but also killing off prominent purebloods and assuming he has a soul fragment of Voldemort in his head, he will likely try to kill Harry, only to either be incapacitated or restrained before that happens.
