I predict that Minnie is going to interrupt this battle between Jr. and Pain, go "Why doth thou care for this wench?" Jr.'s gonna go "I love her," or along those lines, and we done gonna have an incestuous rage/sibling rivalry battle.
Minnie is going to use the tendrils against Jr, but then Jr. is going to gain control and almost attack Minnie, but Mandy is going to interrupt it and say Jr. has earned her respect and Mimi is free to go.
If that all doesn't happen, then we gonna have a bad-ass fight between Jr. and pain and HIM is going to interrupt at a really bad time, at which Jr. will proceed to kick his ass, Jeff will be set free, and HIM will be imprisoned by Grim.
Then we'll move on to afterbirth (hopefully)!