The match
Typically, the first WWE pay-per-view after WrestleMania every year is all about rematches. Interestingly, when Sunday's Payback PPV takes place in Rosemont, Ill., there is only one WrestleMania 32 rematch scheduled. And it's a rematch of one of the Kickoff Show matches from WrestleMania 32. And it's on the Kickoff Show for Payback. Kalisto will defend the United States Championship against Ryback once again.
The players
Kalisto: One-half of the Lucha Dragons (along with Sin Cara), Kalisto is the current and two-time United States Champion and a former NXT Tag Team Champion. By all rights, he should be well on his way to becoming the next Rey Mysterio. But he uh ... isn't really on that track at the moment.
Ryback: The Big Guy has a new mean streak and a no-frills attitude and is attempting to capture his second WWE title. If he wins on Sunday, it will be his first United States title reign.
The story
Kalisto has only had two feuds since moving into singles competition on the WWE main roster. Those two feuds, first against Alberto Del Rio to capture both of his United States titles and now against Ryback, have taken up the entirety of Kalisto's 2016.
The start of the feud between Ryback and Kalisto didn't have much of a build at all. Ryback debuted his new look and attitude and started winning matches in dominating fashion and not even sticking around to get his arm raised in victory. He demanded a match at WrestleMania 32 and he got one. During the WrestleMania Kickoff Show, he and Kalisto wrestled in front of a half-full-at-best house. Kalisto got the victory and retained his title when Ryback got dropkicked into an exposed turnbuckle, hit with a Salida Del Sol, and pinned.
Now, with even less build than before, they'll meet in a rematch on the Payback Kickoff Show. Kalisto wants to retain his title again by defeating someone ridiculously larger than him and Ryback wants to prove he's one of the top guys by holding one of the company's belts. That's all there is to it, but sometimes that's all you need.