So, I’ve seen Fantastic Beasts: The Crimes of Grindelwald 4 times already, and although I have more questions than answers I can think of a few theories.
Aurelius aka Credence can’t be the son of Percival or Kendra. Acording to Ezra Miller, his character was 18 in the first movie (1926), which means he was probably born in 1908. Percival has been in Azkaban since 1891, and it’s very unlikely for to have had a children white in prision. Kendra died in 1899, the same year Ariana did, 9 years before Credence was even born. Following that timeline, he can’t be Ariana’s son either. But what If, when Grindelwald refers to him as Dumbledore’s brother (although he does say Dumbledore per se) he is actually talking to the obscurus. As we know, an obscurus is a parasite, so It could have scaped Ariana’s body after her death and kept feeding from differente hosts until It found Credence. Considering this, the story could go on 2 different ways: either Credence is in fact a nobody who just carries Ariana’s obscurus and Grindelwald gives him the name of Aurelius Dumbledore to create some sort of resentment towards the family and Albus in particular (which for me woulnd’t make sense, specially considering the phoenix). Or, Credence is thruthly a Dumbledore, but not Albus brother. So, when Grindelwald says brother It could still be talking to the obscurus. This makes much more sense to me, because It would mean that the Dumbledore blood is the one that makes possible for the obscurus to have survived that long (remember that Ariana died at age 14, and most obscurus host had passed at 8 or 10 as much) and It will also explain why the phoenix comes to him.
Now, what this would not explain why, when Grindelwald (as Percival Graves) comes to Credence to get his help to find the carrier of the obscurus he says it’s supposed to be a kid around 8 or 10. But, to me, he already must known by that moment that the person he is looking for is a Dumbledore that was born in 1908 or around that time, so he must know it’s older that that. So that’s the only thing that It does not fit. Also, in the first movie, Graves tells Credence that he is a squib, that he knew that From the very begining. That would reinforces the Theory about the obscurus taking the body of a Dumbledore. Credence has no magic, but the obscurus does.
Also, the poems of Thyco, could still be talking about the obscurus, but actually about the Dumbledores. Acording to Yasuf, the poems refer to 3 siblings, a daughter and 2 brothers (Ariana, Albus and Aberforth) and It could also be talking about just Aurelius: “A son cruelly banished. Despair of the daughter. Returned the avenger
with wings from the water".
So, any thougts?
Oh, in case nobody consider this: the ship that sinks where Corvus and Credence are traveling, could be the Titanic.