Hey, I am looking for an expression that has to do with assuring someone, asserting that what you're saying is true, someone "has your word" in other words. Or that you will definitely do something.

Is there something like "May my name not be ... if I don't ..." or "May they don't call me ... if ..."

I have a feeling these are a bit broken translations of the phrase in my language. It's not a common phrase in either language. I'm picturing a superhero or some people in a western using it, it's not in common use.

Anyone have a suggestion what I can use? I need it for a translation.