If you're surv my suggestion for utilizing the 4pc T12 proc would depend on how much focus you have. If it procs when your explosive is on CD (Which it will be most of the time) you can do a few cobras while you wait for it to come off CD IF you WON'T cap on focus by doing so. If it procs and your explosive is on CD and you are almost capped out then you should just use an arcane shot or two (or three) and hit explosive off CD. I'm not a big fan of using Kill Command if you're not BM. Using the 4pc proc on arcane is perfectly fine.