When he tells Xykon that he killed Tsukiko for becoming The Starscream, Xykon's response is "been there, finished that, failed to actually need to have her" (put together with some confront preserving). The evil alien invokes this trope by killing pretty much all of the remaining rogues for their initiatives, with the caveat that, getting a God of cruelty and tyranny, he genuinely considers a fast loss of life a excellent reward.