#2 Do Interbrand storylines

One of the most brilliant storylines in 2015 was the one between the then United States Champion, John Cena, and the then NXT Champion, Kevin Owens. Owens represented NXT, put the yellow-and-black brand over, and belittled the main roster.
The prizefighter went as far as stomping the United States title. In the 2015 edition of Elimination Chamber, Owens took on Cena in a non-title match and defeated the 16-time world champion - thus shocking WWE fans.
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WWE may want to repeat something similar with the current crop of NXT talents as well as main roster talents who have been sitting idle on the roster without getting any storylines or air time.
Having a few of those storylines would benefit everyone involved, and will be a win-win situation for WWE.