*Úni iki úni mumwe would be double negation, so nga is required here.
(Question words affect inverse marking.)
(Also the word order is fairly free, but the question word (lau, pikúni) tends to go near the beginning of the sentence. And both have a rising intonation to indicate that they're questions.)
TODO figure out what conjunction should go where "but" is. Also "with a heavy cudgel."