We all know there were two (2) entities attacking the family. The "HAG" wanted Josh (the father). She grew obsessed with him after his first encounter into the spirit realm when he was a boy. The "HAG" makes a deal with "THE DEMON" who looks like Darth Maul. Only Demons have the power to punch a hole through into our world, but only briefly. The Hag has no power whatsoever. She can only make her presence known in photos and otherwise watch Josh in frustration.
I realized that this DEMON was a CHILD DEMON (not an ADULT DEMON), either that or he was the equivalent of a Demon with a Child mind. He was easily manipulated by the HAG. In the Demon realm, his lair is filled with Carnival attractions and toys, the things a CHILD would want. I immediately got the vibe "Hey, this Demon is a Child himself". When Renai (the mother) hears the argument on the baby monitor radios, she hears a progressively louder retort "I want it" "I want it" I want it NOW!" that's the voice of the Hag getting impatient with the Demon's lack of progress. So the DEMON himself is also easily fooled or defeated in the spirit realm because he's just not that smart.
JOSH was the target of the HAG all along. DALTON was just bait. The HAG promised DALTON to the Demon, knowing full well that the boy would probably be rescued. But she didn't care. She wanted to swap places with JOSH and live out her existence in OUR world, in JOSH'S body, whereas Josh is trapped in the non-corporeal world.