Medium Humanoid (mutant) , Chaotic Evil
Fathar-Kneeg is a delusional mutant who believes that with his "air sword" and few dozen followers he has become one of the nine Rogue Princes. He has not, but that doesn't stop him from being a formidable bandit.
Sneaky Waster. Fathar-Kneeg can disengage as a bonus action.
Multiattack. Fathar-Kneeg makes three attacks with his rapier. Yarun's Imaginary Rapier. Melee Weapon Attack: +8, Reach 5 ft., one target Hit: 9 (1d8+5) psychic damage +1 Magical Weapon. Rending Shower (Recharge 4-6). Each creature in a 10-foot radius of Fathar-Kneeg must make a DC15 Dexterity saving throw or take 12 (3d6) acid damage. On a failed save, there is a 25% chance the acid ruins a metal piece of equipment at random that the creature is carrying. On a successful save, no equipment is ruined and the creature takes half damage. Mutant Rage. Oops. Looks like you've infuriated Fathar-Kneeg. He's seeing red and is currently resistant to nonmagical physical damage. In addition, whenever he hits with an attack, he causes Bleeding on a failed Constitution saving throw (DC14).