#2 The New Day
Back in 2016, directly before the brand split, the Wyatt family feuded with the New Day. It was a compelling month of television, with the bearded cult threatening to begin the downfall of the then-WWE Tag Team Champions. Xavier Woods in particular was affected by Bray Wyatt's mystique, nearly losing himself and his team's identity.
The two teams had a Wyatt Family Compound match, something which would fit right in with today's WWE programming. Wyatt, Braun Strowman, and Erick Rowan also defeated The New Day at Battleground. However, that was the end of the Wyatt Family as we knew it, due to the WWE Draft.
A top AEW star just called one of his colleagues 'spoiled' and 'narcissistic' HERE.
After that, the New Day went back to their energetic and jolly selves on RAW while Wyatt entered an interesting period of his career, which ultimately led to the death of his "Family". Now that he and the New Day are all on SmackDown, The Fiend could finish another job that was started four years ago.
Once Kofi Kingston and Big E lose the SmackDown Tag Team Championship, they could enter their most trying program to date. The Fiend would have some excellent matches against either of them, with both Kingston and Big E worthy of fighting for the Universal Championship.
Woods making his return from injury during this feud would add another layer to it, especially with the fear he showed opposite Bray Wyatt. The Fiend could be the perfect vehicle to facilitate change for the New Day, whether it is a heel turn or a break-up.