The objective is “protector” and the kill count ticks up when your creatures die as is correct for that name objective, but the explainatory text is for pacifist and tells you not to kill too many of your opponent’s creatures.
Yeah, if only it were reasonable to call it “reminder text.” I’m guessing the vast majority of players are like me and don’t even look at the name of the bonus objective, but in fact only read the text description of what must be done to get the bonus ribbons. How on earth did they manage to blatantly screw up not one but two bonus objectives in this event? This is only a half-rhetorical question; after this event I’m honestly curious what the QA setup is, if it even exists.