If You're a Harry Potter Fan, We Definitely Need to Talk About That Crimes of Grindelwald Reveal

Let's say that Credence is really Aurelius and he's Albus's blood brother. Since Albus's mother has been long dead by the time Credence is born (which is probably sometime around 1908), she can't have given birth to him. Which means he would have to come from an affair of his father's, making him a half-brother to the Dumbledore siblings. However, Percival Dumbledore was in Azkaban for attacking the boys who hurt Ariana, so he couldn't have fathered any other sons. I highly doubt the Dementors were letting anyone have conjugal visits in Azkaban and, as we know, Sirius Black as the first person to ever escape the prison. Plus, Percival was also dead before Credence's birth. So unless we do some very creative maths, there's just no possible way that Credence is another Dumbledore sibling.

Let's look at it another angle. Perhaps Credence is a Dumbledore, but not a sibling. Maybe he's the son of another Dumbledore, specifically the only other one who could have a grown son — Aberforth Dumbledore. This would be the most plausible way to relate Credence and Albus, especially since he did have a phoenix come to him. Maybe Aberforth had an affair with a woman who was originally from America, and that's why she was on the boat going back. Or perhaps she was running away from England because of personal trouble. There are a lot of ways this could play out, if we're determined to believe he is related to the Dumbledores in some way.

I can't be the only who how thinks this is most likely the answer. Like I said, none of it adds up. Considering when they both died, Credence is too young to be the son of either Dumbledore parent. Also, if Credence was truly a Dumbledore that his siblings knew of (which Grindelwald seems to imply Albus does), Grindelwald would have known who he was when they met in Fantastic Beasts.

He and Albus were far too close growing up for that little secret not to have been shared before. Another clue to Grindelwald lying is that he tells Credence that he's giving him the name that should have been his birthright, implying that he is naming him and it isn't his actual birth name. As for the phoenix appearing to him "in his time of need," we've seen a phoenix help out people who aren't Dumbledores — Harry Potter for instance — so I'm taking that with a grain of salt. Maybe Credence is that good with animals that a wild phoenix took a liking to him.

But why would Grindelwald lie about Credence being Albus's brother? It's the perfect way to turn him against the other man. By taking him in when his "family" seems to work against him, Grindelwald ensures that Credence will follow his plan and work for him. He gets the power of an Obsurus and a tool to destroy Albus, since he can't personally fight the other wizard.