#4 The Trio of Destruction

Another duo who have been away from the ring for a while now, are the Authors of Pain. The two giant tag team Superstars carved a place for themselves on NXT, but failed to make a similar impact on the main roster. Now sidelined with injuries, when they finally make their return to the ring, they could do so on SmackDown Live.
Given that the Superstar ShakeUp seems extended this time, with the Superstars' first appearance after the ShakeUp determining their brand, this could easily happen.
John Cena's last PPV's name revealed by Kurt Angle? More details HERE
The Authors of Pain could team up with newly free Superstar, Killian Dain. The trio could form a dominating faction and destroy anyone who gets in their way.
#3 The Authority

For once, the McMahon family member who is currently a heel is Shane McMahon. Shane is clearly not done torturing The Miz, and he has time-and-again used the help of various Superstars to do his dirty work.
Bobby Lashley has already helped McMahon one week, and this might be the beginning of a new Authority faction under Shane McMahon.