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...
A Tomb Lord and his minions.
The Tomb Lord is a master of necromantic magic and bone and he can resurrect his minions, create walls of bone and shatter them and he can spin his magic into a storm of bone that can blind you.