#2 Nikki Cross vs. Naomi
Since the very beginning of human civilization, the "fear of the unknown" has been an extremely important part of every individual's life. That said, one of the biggest reasons behind Nikki Cross' SAnitY gimmick being hugely successful in NXT, was her unpredictability.
I'd like to revisit the countless number of times when Cross would seemingly shift from face to heel in NXT -- at times, even leaving experienced and powerful Superstars such as Asuka and Ember Moon confused with her acts. In other words, the basic appeal of Cross' character is that she expertly uses the "fear of the unknown" to mess with her opponent's mind.
Out of every rivalry discussed in this list of ours, Cross feuding with former SmackDown Women's Champion Naomi is perhaps the least likely to take place. However, if the WWE decide to go forward with this feud, they could have Cross stalk Naomi everywhere the latter goes -- right from the ring, to parking lots, to the restaurant when she's having dinner with her husband, fellow SmackDown Superstar Jimmy Uso -- eventually leading to a match between Cross and Naomi at the Fastlane PPV in March of 2019...