If it makes you feel better, I don't think he's as inclined to give into the motives.

[So.... helpful??? He loads his crossbow finally, taking aim-- another torso shot, dead center. He wasn't sure he could get a headshot, but he'd rather not try for fatal blows to begin with.]

Hm, it would be better to disable the limbs really... If I have to, I don't want to kill with this even in self defense.

[Musing to himself for a moment, before back to the topic of Mahiro--] I think his motivation for Mako's death was simply he wanted to be the one to deal the killing blow, not the Teishu. Revenge.