The Sword of Gryffindor can now suck soulsIn canon, the Sword acquired the power of basilisk venom after Harry thrust it in Slytherin Basilisk's brain and venom sack. In this timeline, Ron used it to kill a Dementor.
- If this is the case, that could make the sword even more useful than it was in canon when it comes to horcrux killing. In the first timeline, the sword had basilisk venom in it, which doesas we knowdestroy horcruxes, thus killing the soul fragment within. If the sword can now suck souls, it is likely able to do so without destroying the object itself. That would mean that the Sorting Hat could have its horcrux removed at the cost of nothing more than a new rip.
Harry is working on incomplete information.It is very possible that Harry has only a partial understanding of the events that took place in the vanilla timeline, as well as the loyalties of those people.
- Most significant are his interactions with Snape. Right from the get-go, he takes on an antagonistic role with Snape and uses his Occlumency to block any attempts by Snape (and later Dumbledore) to read his mind. As we all know, in the vanilla timeline, Snape was a triple agent working on Dumbledore's behalf while pretending to be part of Voldemort's coterie. But if we assume that Harry did not have a chance to learn that, then by working against Snape and eventually causing his removal from Hogwarts, then it's very possible that he facilitated the removal of one of the good guys' most valuable agents and caused severe harm to his own cause. There is a reason why Dumbledore was so adamant about defending Snape against Harry's accusations until the mutual antagonism grew so great that something had to give.
- Actually, Harry WAS trying to get off on the right foot with Snape this time around, by showing him that he could be good at potions during the first day and try to impress the sour potions teacher. That, however, backfired completely, as Snape's ego couldn't stand being "shown off by the spawn of James Potter", even though Harry wasn't trying to actively antagonize him. It was Snape that started the antagonism.
The "original" timeline was created by a time-travelerThe entire "agent-in-place" issue is a bit strange, given the many variables in place that could have gone wrong. So, there is a possibility that the "agent-in-place" is actually someone that has done the same trick Harry did, but coming from a "Harry REALLY Wins" timeline, and is working to make things work for Voldemort.
The agent-in-place came from the canon timeline and even helped forge the "Bad Future" that Harry came fromLike the above predicts, the agent-in-place is possibly there to make sure things work for Voldemort; however, the agent comes from the official canon timeline where things more or less ended up well for the Golden Trio. The Agent went back to the timeline that saw nearly everyone Harry loved die in horrible ways and even outed Snape as a spy for the Order of the Phoenix. The agent would still be present in the new timeline that Harry went to and noticing Harry is acting differently, they likely deduce that Harry did the same thing he/she did and so makes modifications to try and eliminate Harry much earlier like amplifying Vernon Dursley's less than desirable traits.