#1 Luke Harper
The most misused wrestler on the roster this year is Luke Harper, and it's not even close.
Luke Harper, formerly Brodie Lee, is legitimately one of the most impressive big men in wrestling today. He's a powerhouse who can fly like a cruiserweight, and he can tell a story during a match through facial expressions better than just about anybody. WWE had a golden opportunity to establish Harper has a top guy or, at least, a solid mid-card act for the SmackDown brand.
But, of course, they squandered it.
Having been ousted by Bray Wyatt at the beginning of the year, he could've had a classic redemption story against his former leader. Instead, he was fed to Randy Orton at the Elimination Chamber PPV. When he and AJ Styles were declared co-winners of a battle royal to determine the #1 Contender to Wyatt's WWE Championship at WrestleMania, they once again had an opportunity to tell that same story.
Instead, he lost to Styles, who didn't even end up wrestling Wyatt at WrestleMania anyway. After inexplicably disappearing from television for a month, Harper returned to SmackDown in a losing effort against Wyatt (again...they could've told that story), then feuded with Erick Rowan, the least significant former Wyatt Family member by far. Though he defeated Rowan at Backlash, nobody seemed to care about anything that was going on between the two bearded behemoths.
Since Backlash in May, Harper has only appeared on WWE television twice, once in a losing effort to Jinder Mahal and once in a Battle Royal for a U.S. Championship opportunity, which saw him get eliminated by Mojo Rawley to little fanfare and to the crowd's chagrin. Now, he's...teaming with Erick Rowan again? Why do these two like each other again? Why are they holding giant hammers? What is sacred anymore?
WWE had so many chances to build a new star in Luke Harper. Instead, they messed it up to a point where he may never taste the spotlight again.