Why you should never take prisoners.
One of the focal points, and a large source of fun, in Deus Ex: Human Revolution was the ability to radically customize your cybernetic enhancements to specialize yourself into being anything from a hacking wunderkind to a walking tank that spits out death. Unfortunately, once you had set yourself on your chosen path, it was really hard to experiment without another 60+ hour playthrough. Until the Missing Link DLC was released, that is.