He already has the perfect nickname, Effortless James, but how does a crowd shout that out in unison? "Initials".
Initials historically signify greatness: MJ, DT, KG, etc. so JB could work. Fans could chant it when he hits big plays and the TV people would happily and excitedly propagate it.
But, that's too mundane for "the basketball capital of the world". Plus, he's quickly shown he could be one of the best ever at UConn, has a nickname that captures his ability to make big plays look easy and its initials (EJ) would be easy to chant.
EJ, EJ, EJ would shake Gampel and the XL center when he makes big plays.