#1 A big heel turn should happen at the right time

As we previously said, in the past many shocking heel turns have happened in the company, but one thing to note is the fact that most of them happened either on a pay-per-view, or after a pay-per-view.
At WWE Payback 2014, The Shield (Seth Rollins, Dean Ambrose, and Roman Reigns) defeated The Evolution (Randy Orton, Batista, and Triple H) in a six-man tag team match.
Look who just shut down all of Tony Khan's critics! More HERE.
The next night on Raw, Batista quit the WWE, and then Triple H came up with his "Plan B". His idea became one of the most shocking decisions ever, as Rollins turned on his Shield brothers by attacking them with a steel chair.
Same could happen with Ambrose as well, because currently there is a match set for the upcoming WWE Super Show-Down where The Shield will face Strowman, Ziggler, and McIntyre. Ambrose could turn heel during or after this match.