Closet Key: Nikki was apparently one of these for Helen. Even to send just one crew member, or to send in Engiesnote a poor choice because they do half the attack damage of most races and Zoltansnote a poor choice because they have only 70% of the health of most races, although Advanced Edition has them explode upon death, enabling suicide bomb strategies if no other choice of boarders are available, regardless of how much more effective it is to just keep the entire crew on board.
The gap between present day and the Mass Effect times has been filled by the Deus Ex games’ events. That being said, he never really does anything actively villainous either. Does Not Like Shoes: Ursula may be this, since she always wears open toed footwear (either flip flops or sandals).