Kinetic Reservoir, so it would be your build with KR at 5 instead of at 6. But I'm still only 24 with my commo, and currently prioritized KR last, so I'm currently: 6 Vigor, 6 IM, 6 Growing Rage, 3 KR, 1 Singularity, and 1 Neutron Stomp. I found before level 24 (when I could respec into Growing Rage), when I had KR at 6, I was rarely falling below 70% power, if even that. So I figured I could give up some KR. Still trying to suss out if I can spam everything I want and still keep enough power through the end of a Guardian run with only 3 KR. So far, I think so but need a few more runs to double check. Depending on how much KR you really need to keep enough power without needing pots, you might even be able to squeeze in a third taunt: the other insta-taunt (1 in Force Hammer).