What happened to the scary, red-faced demon from Insidious series?
According to Wikipedia , the creatures just exist in the astral plane unless they find a body to contact the physical world. , the article further states Ellise and Dalton get attacked by the red figure but they manage to somehow lose him. Which implies he still exits in that dimension only has no way left to express himself on the physical world.
Elise explains that Dalton is not in a coma; he was born with the ability to travel mentally to the astral plane, and had been doing so in his sleep, believing his abilities to merely be dreams. He had traveled too far and became lost in a purgatory realm called "The Further", a place inhabited by the tortured souls of the dead. Without his mental presence, Dalton's body appears comatose and spirits can use it to enter the physical world. Josh is skeptical until he realizes that drawings in Dalton's bedroom hinted at his astral projection abilities and the same red-faced demon Lorraine had seen.