#4 Killian Dain
The next generation of monsters is way different than their counterparts from previous eras. They run like athletes and fly like a cruiserweight, therefore, Killian Dain is no exception. He replaced Sawyer Fulton in Sanity, at that time many people didn't know what he could do in the ring, but as the time progressed, he impressed everyone with his performance. He delivered a freaking coast to coast in the War Games match, a move only performed by Shane O Mac and RVD.
There were several rumours this year that Sanity is getting a call-up to the main roster but that didn't happen but possibly they will debut next year. Imagine a feud between Braun Strowman and Killian Dain and how many tickets that will sell in any arena.