I like this in Sixto's Zabèl: "Gen priyè pou chase move lespri, men pa gen priye pou chase vakabon. Men vakabon, se an vakabon ou aji avè'l pou w regle ak li".. To be sure about the last part, is it saying you have to stoop to someone's level...?

Yes. basically.  "vakabon", here, translates a villain, scoundrel, or someone with whom you can't play "nice".
examples
Vòlè, se an vòlè ou aji ak sa pou'w regle ak yo.
Avadra, se an avadra ou aji ak sa pou'w regle ak yo.
Pye sal, se an pye sal ou aji ak sa pou'w regle ak yo.
Bandi, se an bandi ou aji ak sa pou w regle ak li.
You must stoop down to their level in order to deal with them.

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