Use Cursed Thrall to your advantage.
Krughor is a Hive Ogre that is one of the possible outcomes from a Reciprocal Rune.
Tactics[]
When summoned, Krughor has a shield impervious to all forms of gunfire, and spawns with many Cursed Thrall surrounding him. The explosions of any Cursed Thrall near Krughor will take out his shield and leave him temporarily vulnerable.