AU to the end of the movie. When Grindelwald finds out Credence is the obscurial he manages to convince him to come with him. But Credence doesn't fully trust him after his betrayal and finds out he is an impostor. So Grindelwald takes him to see real Graves and threatens to maim/kill him if Credence doesn't do as he wished.
Graves/Credence, Grindelwald uses Graves as leverage