#1 "The Fiend" Bray Wyatt
The first name that came to mind for a potential opponent for Killer Kross was obviously Bray Wyatt. He's remade himself into arguably the biggest star in WWE since Becky Lynch's fire has been slightly fading due to lack of quality foes. She's still the biggest star in the company, but Wyatt has ruled the last five months.
As with Aleister Black and potentially Samoa Joe, a feud with Wyatt would be multi-layered. Wyatt has the Firefly Funhouse and that's something that no one has really dissected yet. Someone with a strong psychological game could do that and Kross is one of the best in pro wrestling today with mind games.
Corey Graves deleted his Tweet! More details HERE.
If he didn't get anywhere with the sweater-clad Funhouse host, then things would obviously lead to a battle with the Fiend himself. The Fiend usually ends feuds or takes care of business in the ring. Extreme Rules takes place in the beginning of summer, so they could have a hardcore match or some other type of gimmick match at the PPV.
SmackDown in particular is in need of some main-event level stars. There's Wyatt, Daniel Bryan, Roman Reigns and potentially Strowman. King Corbin, the Miz and Kofi Kingston are also in play at times, but the blue brand needs legitimate and believable threats. I think Kross could slide into the main event as a top heel if given the chance.