Fast

Fast is a boss modifier in Diablo III, and acts as a frenzy effect, increasing movement and attack speed. While seemingly innocuous on its own, this modifier has the potential (as all other utility modifiers) to be part of a very dangerous combination. As an example, a boss with both fast and cold aura will be able to inflict significant damage. A player would be well-advised to slow or otherwise snare these bosses with skills such as entangling shot or ray of frost.