So while yes, World Domination is high on Grindlegrave's list of priorities it wasn't his only reason for wanting to find the Obscurus. Albus left Grindlewald when Albus felt he had to choose between him and his family. Therefore, the solution to getting Albus back by his side is simple. He'll just make Albus a new family. The Obscurus, a child powerful enough to make his enemies tremble before him and hopefully doe-eyed and needy enough to prey on Albus' paternal instincts, is the perfect pawn.
Only then the events of the movie happen, and his perfect baby trap turns out to be a nearly fully grown man. Eh, he'll roll with it. So after vague handwaving of events at the train station, Grindlewald convinces Creedence to escape with him and seek asylum with Dumbledore.
TLDR: Grindlewald to show up on Dumbledore's doorstep with Creedence in an attempt to Baby Trap him. Against all odds, it works.
Bonus points for not dead and extremely pissed off OG Graves trying to track them down, as a world without Colin Farrell's perfect face is not a world in which I want to live.
Dumbledore/Grindelwald + Creedence - the Baby Trap
Only then the events of the movie happen, and his perfect baby trap turns out to be a nearly fully grown man. Eh, he'll roll with it. So after vague handwaving of events at the train station, Grindlewald convinces Creedence to escape with him and seek asylum with Dumbledore.
TLDR: Grindlewald to show up on Dumbledore's doorstep with Creedence in an attempt to Baby Trap him. Against all odds, it works.
Bonus points for not dead and extremely pissed off OG Graves trying to track them down, as a world without Colin Farrell's perfect face is not a world in which I want to live.