The easiest way to do this is wait until you get the ability to brand enemies late in the game. After the mission and learning the skill, buy the skill for dispatch, then play the next mission. "The Power of the Wraith” has you help a captain in a recruitment power struggle, the minute the struggle is over but before the group has walked away (it should say "recruitment successful" press Down on the d-pad and kill the captain. The game will register the trophy and then tell you that you failed the mission. This is fine because you can retry from that point, and got this annoying trophy out of the way.