#3. Brock Lesnar

Like it or not, Brock Lesnar still holds the Money in the Bank contract that allows him to cash in on the Universal Champion or the WWE Champion any time he wants. Since WWE would like to bring back some of the big guns in time for SummerSlam 2019, Brock Lesnar could announce his cash in at SummerSlam 2019.
After squandering the men's Money in the Bank briefcase for the last two successive years, WWE would be looking forward to not wasting the briefcase this year. Brock Lesnar might appear on the RAW after Extreme Rules to announce his cash in at SummerSlam 2019. Even if he does not announce his cash in, there is still a huge chance for the Beast Incarnate to cash in at the event. Hence, Lesnar is always a threat for the World Champion.
Becky Lynch has been challenged HERE.