Should still be tied to RI for tank busters. The target requirement should be optional. It should apply the effect like usual if you have a target, but if not then it should work on you alone very similarly to bloodbath.

Using decimate on top of 2 chaotic cyclones is amazing in packs. RI isnt as good if you have the cooldowns to do this. Just plan it out a little. On single target, RI is superior. If you are about to get smashed by a buster, RI could be needed to survive. I find both very useful depending on the situation and dont really mind at all if they are tied together. Its the target swapping that bothers me.