Multiattack. The aurumach makes three Manifested Blade or Gleaming Ray attacks.

Manifested Blade. Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit: 23 (4d8 + 5) force damage.

Gleaming Ray. Ranged Spell Attack: +11 to hit, range 120 ft., one target. Hit: 24 (3d12 + 5) force damage.

Aura of Blades. The aurumach manifests a spectral, golden aura of blades around itself. While this aura is manifested, each creature that starts its turn within 10 feet of the aurumach must make a DC 19 Dexterity saving throw, taking 16 (3d10) force damage on a failed save, or half as much damage on a successful one. The aura disappears after 1 minute, when the aurumach has the incapacitated condition or dies, or when the aurumach uses a bonus action to end it.

Invoke Weakness (Recharge 5–6). The aurumach attempts to use its magic to weaken the defenses of a creature it can see within 120 feet of itself. The target must succeed on a DC 19 Wisdom saving throw or become cursed until the end of the aurumach's next turn. The next time the aurumach hits the cursed target with a Manifested Blade or Gleaming Ray attack, the target takes an extra 27 (6d8) force damage.