since the WAZ are still technically alive, you should be able to execute them anyway you could a regular human. i would think that electricity would make a particularly effective weapon since runners can't outrun it and behemoths would still conduct it, no matter how thick their armor is. you would just have to figure out some way to project it. i would think some kind of ionization laser to give your target a negative charge. then the gun would emit a massive jolt of electricity which would travel to the target and, BAMM SONN!

on an unrelated note, eviebae, i love your sig.