he can knock your hero out for several seconds, thats why it is wise to keep a save distance. here is how to knock it down (spoiler): Spoiler When he is moving he is invulnerable to damage. He will also block arrows from the balista with his club. But if he is charging his power club attack, you can shoot it with an arrow from the balista and knock it down. then you have a window of a few seconds to do damage. a spell like chain lightning or fire wall can do wonders. There are a few more tips i could give, to beat the first boss encounter, but this should help alot.