Author's Saving Throw: WWE slid dangerously close to screwing up KO's return from injury in 2019 by having the white-hot Kofi Kingston replaced in a WWE Title match by KO at the last moment by Vince Mcmahon fiat with absolutely no setup. Given that KO was clearly meant to be returning as a Face, this had the potential to go Batista-in-2014 levels of sideways. Clearly WWE learned their lesson to some point this time around, because they made very sure to have KO acknowledge that Kofi was getting screwed and even team with him at one point.
Awesome Music: His WWE theme, "Fight", is a slow tempo hard-hitting hard rock piece that incites the chant "FIGHT! OWENS! FIGHT!". It wouldn't sound out of place in a Training Montage.
Badass Decay: KO was an absolute monster in NXT, where he was the Big BadKnight of Cerebus who terrorized the entire roster and created a much darker mood shift for the division by shelfing several top stars, and showed flashes of it on the main roster until they gave his first feud to Cena. While Owens managed to win the first matchclean, two subsequent losses effectively made that win look like a fluke. After that, he became the Intercontinental Champion, which seems good on paper, but at the time said title had lost so much prestige it was considered by many fans to be the kiss of death for a wrestler. While he wasn't booked into a losing streak like previous Intercontinental Champions, the lack of any meaningful feuds and the fact that he was now fighting guys like Ryback (who hadn't been relevant in years) and Dean Ambrose (another talented guy who the WWE was treating like a jobber) took away a lot of interest in his matches. In non-wrestling terms, he went from being an outright Hero Killer, to being a glorified Elite Mook. The fact that he was also toned down from a highly intelligent, ruthless sociopath and Magnificent Bastard who was just as much a physical threat as a mental one to a generic cowardly heel (a common critique is that he went from "Fight Owens Fight!" on NXT, to "Run Owens Run!" on the main roster) certainly didn't help matters.
Even becoming the WWE Universal Champion, which should be a crowning achievement, did absolutely nothing to quell this. First off, there's the fact that Triple H interfered and Pedigreed Roman Reigns to leave him prone for a cover by Seth Rollins, then in a Shocking Swerve did the same to Rollins so that Owens could cover him, both figuratively and literally handing the championship to Kevin Owens. As the champ, Owens has been firmly in the role of a cowardly heel as well as the fifth most important person at best out of seven in the overarching storyline involving his own title reign (certainly behind Rollins, Triple H [who hasn't even shown up since that night!], Stephanie McMahon and Mick Foley; and it's debatable where he ranks compared to Reigns and Chris Jericho). To date he hasn't retained his belt cleanly at all, needing to rely on the help of his new best friend Jericho to cheat. His character has become comically incompetent, the badass he once was in NXT is non-existent, and it's pretty clear that if he were to fight the likes of Rollins or Reigns with no Jericho or cheating around, he would lose with ease. It's even been noted that Reigns has come off stronger than Owens at the end of every single segment/match since he became Owens' main challenger in the feud, thus further burying his credibility.
Character Rerailment: After months of Badass Decay (as discussed above), his betrayal and hellacious beatdown of Chris Jericho has gone a good way in starting to repair his Badass sociopath character from NXT.
He got derailed again during his 2017 feud with AJ Styles, where Shane McMahon was constantly inserting himself into it. Sami Zayn's heel turn stole a lot of KO's thunder, and the booking of the two of them as juvenile assholes instead of credible threats wasn't helping. That all changed on the 3/13 Smackdown, where he and Zayn beat the living hell out of Shane, including a steel chair to the throat spot on the ring post, and a powerbomb onto scaffolding equipment backstage. They followed it up the next week by beating down the beloved (and just medically-cleared) Daniel Bryan, Kevin powerbombing him onto the ring apron.
Designated Villain: From mid-2017 until now. It has been pointed out (most recently by Jim Sterling and Cultaholic) that from the moment Shane McMahon screwed him over at Summerslam 2017, Owens has actually done nothing that wasn't either a) a retaliation for unfair treatment, b) something that ten years ago, was getting Steve Austin monster cheers, or c) cowardly out of sheer self-preservation. Shane screwed Owens over constantly, Kurt Angle continued the unfair treatment, and he's spent the past two months being targeted by Braun Strowman for no reason other than people think it's funny when Braun terrorizes people. Against anyone who isn't Strowman, Owens gets cheered for his likable and sarcastic personality, and if you took away Shane's and Kurt's Popularity Power, any other authority figure treating a wrestler like that would be clearly presented as a heel and booed out of the building.
Attacking non wrestlers, going out his way to injure wrestler after matches, spitting on audience members, burying the company itself as well as adjacent companies, embodying the negative traits other wrestlers get called out on but getting a free pass? Yeah, his time in SCUM was this full force.
The early trappings of his run as WWE's latest quickly-rising heel juggernaut has many of the same features.
At PWG BOLA 2013, in a promo alongside Adam Cole and the Young Bucks, Kevin Steen defended his lack of a title belt by proclaiming that he was "The Champion of the Universe". Just over three years later, Kevin Owens won the WWE Universal Championship.
His relationship with Sami Zayn comes off as a bitter breakup, starting when Owens came out to celebrate Zayn's NXT title win (including hugging him, exchanging forehead kisses, and cuddling on the ring apron) and then turned around and powerbombed him into oblivion. The deep, unending, irrational hatred that Steen had for Generico has almost certainly continued to their later incarnations, no matter how much Owens denies it, and it proves Steen's statement about how they were "destined to do this forever." That adds the Foe Yay component that makes their entire enmity seem like some kind of love/hate Masochism Tango.
To say nothing of their grudge match at Final Battle 2010, where Steen outright kissed Generico on the lips. If you rewatch the entire Steen/Generico feud with Homoerotic Subtext/Foe Romance Subtext in mind, hearing Steen call Generico an "infection" that he just can't get rid of, the constant mind games, and his fixation with Generico's mask and desire to show the world Generico's "ugly" face can be read as Steen being attracted and/or in love with Generico and trying to sublimate it through violence directed at the object of his "affection".
Zayn and Owens are even MORE affectionate as a heel team, constantly hugging and hanging all over each other, and Owens once again kissing Zayn, this time on live television. AJ Styles even gave them a Portmanteau Couple Name of "Kami". They were described at the beginning of their Ride Along episode as Like an Old Married Couple, and mentioned a time during their indie days they "accidentally" watched a porno together.
His relationship with Chris Jericho before February 13. The two always referred to the other as "My best friend", they were rarely out of each other's company, and very affectionate with one another (Owens even kissed Jericho on the cheek when he helped him beat Roman at Hell in a Cell 2016). When Owens broke Jericho's trust, he was wracked with guilt and was desperate for his forgiveness. Going so far as to stand outside Jericho's dressing room, pleading with him to accept his apology.
I Knew It!: As soon as "Sami Zayn" was signed to NXT, there were talks among fans of him winning the title, getting congratulated by Kevin Steen and then taking a package pile driver. Sure enough, the sequence ended up happening almost to the letter.
When Owens asked to become an honorary member of The New Day, fans immediately began making guesses as to how long it would take him to turn on them this time. The answer: a week.
By association at ROH Goldrush in 2010 when the fans started chanting for his tag team partner, Steve Corino (then known as "Mr. Wrestling").
There are plenty of people who cheered Owens (who's technically the heel in the pairing) during his fight with John Cena at Elimination Chamberthough part of that is fans rooting for anyone who can break Cena's Invincible Hero status.
The Scrappy: Along with Generico early on in the two's tenure before they became an official team, Ring of Honor fans hated his presence and felt he didn't deserve to be in the company. Every little detail of his matches in ROH would be picked apart for any flaws, as well as constant complaints about his supposed lack of condition and or sloppiness. While he's become wildly popular since getting rescued from the heap he still gets his fair share of flak from those who prefer their wrestlers to be aesthetically well-built instead of Acrofatic (which some say might be the only thing keeping him from becoming a transcendent superstar).