Devil could use more representation, and ideally a support spell or two next time we go to Innistrad, but for a tribe that barely exists outside of one plane, its doing quite well
Despite the Commander 2011 precons overvaluation on secondary markets, the decklists themselves havent appreciated as much as you might think
The many popular 4-color and 5-color commander decks like Jodah, the Unifier, the Ur-Dragon, Atraxa (both), and Slivers should have a natural home for Wrenn and Realmbreaker
Nadu's ability only triggers twice per creature per turn, but if you can remove a creature from play and return it, that counter resets
Needless to say, the possibilities for creating your Cube are limited only by your own imagination