You probably don't want the bullet behavior, you probably want to use Follow. If you want the void to be very smart and exploit the maze for shortcuts to the player you want to use the pathfinding behavior.
Another option is the Moveto behavior.
If using pathfinding or Moveto what you want is every second or so (or three) see if the void is too close or too far from the player with the distance function. If too far update the behavior again so it heads for the player, or have it stop if too close.
yours
winkr7