jatasēña is the word for warning. Here it is the object of setesse, which is se with a 3rd person paucal (or collective) source and a 3rd person plural beneficiary, so something like ‘they warn them’, with they being a cohesive group and them being multiple people. And ien, of course, renames the object of se.
setesse jatasēña ien sasēsse jasēsi jasēñi;
[se.tes.sĕ ja.ta.zeː.ɲə̆ jɛn sa.zeˑs.sĕ ja.zeː.zi ja.zeː.ɲi]
They warn them that their kidneys’ spots are dangerous.