What was the important quality that the Plains Indians saw as very important for their warriors to possess and in what ways were they
expected to show this quality?

They wanted the braves to possesss experience. Wheither got their head shaved, it was a sign of their quality.

Explanation:

its he tried to add or forgive me but he said forego

greet them:

buenas noches.

that is considered night time which is when "good night" is used.