Ace Austin
The easiest comparison I can make for Ace Austin is if you blended Rich Swann and Finn Balor. He's primarily an athletic high-flyer, but some of the moves he pulls out are akin to those performed by Swann, Ricochet and Will Ospreay. While he still has a ways to go and is still working to be on the levels of Ricochet and Ospreay, he's still one of the best middleweight/cruiserweight workers in the world.
He also has a built-in gimmick with playing cards as his name is obviously Ace and he is routinely seen with a deck of cards. He also sports a tattoo of some cards on one of his upper arms.
Austin's matches in MLW with Swann, Teddy Hart and DJZ were phenomenal and should at least give those not familiar with his work a taste of the type of style he brings to the ring.
Should WWE give him a chance, and they'd be crazy not to, the matches he could put on with the likes of Andrade, Ali, Balor and Richochet would certainly wow the crowds.