"Fantastic Beasts: The Crimes of Grindelwald", unlike the first movie, has a lot of information a fan can piggyback off in regards to what is going on between characters and information regarding that character him or herself. The information is also secretive and may also be a series of hunches like the identity of Credence Barebone, a boy who desperately wants to know who he is. While Grindelwald DID reveal who he is, what is the lie, and what is truth in a story that is meant to deceive the audience? Leta hiding information regarding her brother Corvus for instance. At most all the scenarios are perceptions of understanding with no other details known because, like Leta, it is kept hidden, or Grindelwald himself. There are two important moments that one should know as key details; one, the moment when Albus Dumbledore told of a story of birds and two, his hunch on what could happen to save Credence.
Now I had hoped there was a link between the Pheonix story and the Obscurus, but so far I found nothing and yet could be in front of me. The purpose of THIS article is My Theory on What will Become of the Obscurus. But first I want to fit in the phoenix bit as, while it is important, it serves no link to the Obscurus.... and yet it might.
The Story of the Pheonix
Albus claims that the has an affinity for birds in response to Newt saying that he knew he would not disregard the opportunity to save the Thunderbird, to which Albus replies "There's a story that a Pheonix will come to a Dumbledore in need" (FBCOG). "THEY" say his Great-Great-Grandfather had one who died, and when he died the Pheonix left and never returned. I don't know who "THEY" is, I assume and one might assume his family members. If it is associating with his family, the "story" part is remaining intact. Families tell stories to each other, Albus heard a story from his own family that his great-great-grandfather had one and it is part of the family tree. Given it is a story then, Albus has no idea if it is true only that he was fascinated by the story that he adopted it as true, making it a belief. One bird did appear by and alongside Credence, which is revealed to be a Pheonix.
Now, the reveal is taken by surprise yet we are called back to what Albus said and therefore Credence is, in fact, a Dumbledore. My initial thought, given Grindelwald's capabilities, he was somehow able to alter the bird's DNA into a Pheonix (which is a theory), But alas Grindelwald looked into who he was after the fact he made a mistake in the first film to find who he is. The path also was laid out by him to push Credence into confronting his true self by Grindelwald's lips. If anything else is to go by, the execution of the Half-Elf, Irma Dugard, is that to keep who he actually is out of mind because he will accept it. This means he is not a Dumbledore, but as she did not actually say anything, she might have said he was.
My question then is: WIll Albus recognize the bird beside Credence? No, as he was bringing up a story, he has no idea its true. The Sole idea was to have an effect on the audience so when it is revealed, we put the pieces together as that it is true. However, it does not mean that the Pheonix would not recognize the name or his face, or have any other connection to his family line. He does end up with a Pheonix. The Pheonix in Credence's about also signifies a rebirth in the form of a Plot or Character tool. He found out he is of another name and that is a sign of Rebirth.
An Obscurial Theory
An Obscurus is born of a witch or wizard who is forced to not use the magic that he or she knows they have that "grows in the absence of love, as a Dark Twin, an only friend". Albus goes on to say what is the most important detail to know about the future from that moment in the film alone and the future in the series. "If Credence has a real brother or sister out there that can take its place, he might be saved". (FBCOG)
"its" referring to "Obscurus". The last sentence is f importance in regarding the future of Credence, but not Credence himself as Credence, but what will become of the Obscurus. My understanding is that if Credence has a brother/sister then the Obscurus can be transferred over to that person, therefore saving Credence. This means, his brother or sister will have to die, and that Albus is willing to kill one to save another. Given we know that his name is Aurelius Dumbledore, his "real brother and sister" is Albus, Aberforth, and Ariana. Ariana, theoretically, died to her inability to control magic and her mother's and Albus's carelessness to help her. Theoretically, she was an Obscurial.
It is also good to know that an Obscurus needs a host to survive, and as Grindelwald in the form of Percival Graves said, "It is useless without a host". So what remains is a theory that Albus will transfer the Obscurus from Credence into the body of Ariana. If the Obscurus needs a host, it needs a living and breathing host to survive. This means that it can die out when the body is dead. Theoretically speaking, if Albus places the Obscurus in Ariana, it becomes useless because the body can not be used because the body is dead. Therefore, it is TRAPPED.
This all assuming he is a dumbledore and therefore his "real" brother and sister" because he could also have another brother or sister worth knowing. A question then remains: Where was the Pheonix before the birth of Credence? Is the Pheonix by Credence, Fawkes? (Fawkes is a dual meaning that references Guy Fawkes and Parliament and as a play on words that is Faux or fake).
Bonus Note: I do wonder what if the little bird was in fact a Raven Chick that was in the hands of Credence. That would really link him to Lestrange and create more of a rounded mystery. and if the Raven transforms to a Pheonix... then Leta would be reborn.
