imo bs or upheaval and determination for sure either if it would go on blood rage or reave stances, and dont forget about at the gates - its nice burst tool and helps literally kill poor (khitai etc) clothies/lights in one cc, imo wtw is overrated and it totally sucks on zerker since you honestly got already to many tools to gain stacks - and guess what happen when you reach 15 - you have to reset it manually cos blood frenzy has 1 min cd ;( and thats why imo only option is to slot it in pve in static fights where you have dps race and nn to use dete.