Would be cool, especially with blood commander, but I think it should only apply on strikes. It would be way too unfair if it was applied to skills like meteor shower, maul, double strike, intimidate, and zerker.
Meditation "Focus your anger and use it to sync it with the arcane battle:Consume your rage and gain energy(or hp? or both?) in return: It should improve with rage and the "stat" requirement would be at least 25% or 50% rage bar: I didn't thought about the % because i don't know how rage works in number. It should have a 2 rounds warmup and 2 rounds (maybe 3) of cooldown.
It also could make it to consume your opponent rage but that might become to OP.
This could rezolve mercenaries energy regain problem while it still serve as a tactical purpose since your sacrificing your own rage.