The Barbarian battles a Skeletal Ballista inside Maugan's Works.
There are two positioned at the edges of this room and rather than dealing with the swarming skeleton pack at the doorway the Barbarian chooses to neutralise the Ballistas first. They have a massive range, in fact, off-screen and pack a devastating punch. If the Ballista has the Multishot affix it will fire three Ballista shots instead of the usual one.