[Not the first time someone's threatened to kill you and you're sure it won't be the last. But it's not fun, so you may as well point out the futility of the action. You've noticed your loads seem to work differently here, only affecting you instead of the entire timeline, so you might as well be blunt.]

You'd be wasting your time. If you kill me, I'd just come back and try again. But that doesn't mean I'll do a bad job. I'll do my best, promise!