Indeed, to say that Cabeza de Vaca the famous Spanish explorer and the others who survived the expedition "had been so utterly transformed" by their experience is not far from the truth.
For example, we are told that with excitement they started their expedition to discover "the New World" hoping to find gold and settle, little did they know that they will fall into slavery.
Consider, for those who survived they saw what it meant; the pain of dying, after only 242 men out of over 600 managed to reach Apalachee Bay. Further into their journey due to rough seas only two boats with 40 survivors were left and finally 4 out of 600 men that started the expedition were alive. At this point, the 4 survivors became subjected to slavery by Native Americans. It took about 10 years before Cabeza de Vaca could return to Mexico after their initial departure.
I'd say the stressed syllables are "nor mars and nor wars" and non stressed are "his sword and quick fire shall burn" sorry if this is incorrect pls let me know if it was!