#4 Sami Zayn
Sami Zayn had a memorable debut on the main roster when he was introduced by Bret Hart as a challenger to John Cena in the weekly "US Title Open Challenge". An excellent match saw Sami Zayn falling short, but gaining the respect of the fans after having a tremendous showing. However, he got injured during the bout, hence delaying his roster call-up.
After his comeback he was involved in boring feuds, most of which he lost, while his friend turned enemy Kevin Owens bagged title after title. Finally, when he snapped and turned on the fans, it seemed like things were finally happening for him.
A top AEW star just called one of his colleagues 'spoiled' and 'narcissistic' HERE.
However, he was caught in a short-lived partnership with Owens which went nowhere. His work against Bobby Lashley was one of the most underwhelming feuds of 2018, and he has been out since then due to injury.
What can be done:
Sami is very talented in the ring. However, his mic skills do not do justice to his skills between the ropes. Given how a heel needs to play with the crowd, Sami will always be better suited as a babyface. He should have a character who speaks less and makes his wrestling do the talking.
Zayn should be given lengthy feuds against a mid-card champion, similar to his work with Neville in NXT, where he continued to pursue the NXT title, eventually putting his career on the line for the title. A few US title or Intercontinental title reigns under his belt will greatly help his cause to ascend to the top of the ladder.