"Tom Riddle Sr. is a Muggle — a No-Maj if you prefer. He's not magical in any way. Credence, on the other hand, is definitely not a Muggle. If you've seen Fantastic Beasts, then you know that Credence is actually an Obscurial — a witch or wizard who has repressed his or her magic so much that it erupts into an Obscurus, an object of dark magic capable of mass destruction and murder. If Credence were Tom Riddle Sr, then he's no muggle, he's a wizard. Furthermore, there's the small fact that Credence may or may not have died at the end of the movie (though, he probably didn't). If Credence were Tom Riddle, he would need to be alive in 1943 so that Voldemort could kill him." -
What do you think of this theory?