My fiancees step boy are looking to 302 him and take over everything, Can he give me power of attorney?

they told him they want him to suffer and because their mother is dead they are looking to start trouble and since we are engaged. we would like to know if they can get it or can he give it to me so they can't make him suffer. thats what they want we need some answers to see if we cam stop what they are planning to do.