I got Limbo about a week ago and have been able to level him up past rank 13.
Like holy ****, I was wondering why so many people complained about this guy and now I finally see why.
Without using any of his abilities, Limbo is completely ****ed. Seriously, half the time I'm struggling to stay in the Rift and not get ass-blasted by everything around me.
But the problem is, once you're in the Rift, you can only kill enemies one at a ****ing time unless you cast Cataclysm and banish a bunch of enemies who will probably kill you while you're Rift walking.
Playing as Limbo is such a struggle and just isn't fun nor rewarding to play.