I think it means if you hurt my friends, I will kill you.
Achilles this is because of the story of Achilles heel which was the weak spot of a demi god that was untouchable in every spot other than the heel.
The true meaning of friendship is to be by someone side through thick and thin, Even if they were to change, you are suppose to be the bigger person. You are suppose to love and respect on every level. Also guide them, when you feel as though they are falling etc.
A, because hyphen is not a 1 syllable word.
