Champion/Paragon/Riftblade is pretty insane. Go full champ with leftovers in Paragon and leave RB at 0 for the crit buff proc. It may seem like an overwhelming amount of useful abilities, but they're all very easy to macro together. Personally, I go with an "Anytime style" macro and a "Finisher" macro. The "Anytime style" macro has bloodthirst, all the off GCD reactives, rising waterfall (or whatever.. the Paragon follow-up) with Power Strike last.