Riddle will bypass his Unbreakable Vow regarding the Tournament
Riddle's Vow was to "in the event that [Harry is] the outright winner of the New Triwizard Tournament, cease all attempts to introduce, promote, or pass legislation regarding the rights of non-pureblooded witches and wizards in the areas of employment, healthcare, and marriage, including any legislation encouraging or requiring people to marry or not marry on the basis of blood status alone". He already tried once to bypass it by passing his legislation before the Tournament finished. It seems plausible that he will eventually point out to the judges that "Rigel" ought to be disqualified and "his" win annulled, since Rigel lied about being a pureblood and was therefore competing in the wrong category, against the wrong opponents, unfairly disadvantaging the purebloods; in fact, as a result of Rigel's deception, there were no purebloods in the final three tasks at all. Rigel proved to be the best duellist, but should have been facing Krum, not Fleur, in the Lake and the Climb and the Maze, which might have given an entirely different result. Thus, "his" win ought to be voided.
Result: Jossed. Riddle tried to exploit the Vow to catch Rigel, instead of nullifying it.
