Duergar Resilience. The duergar has advantage on saving throws against poison, spells, and illusions, as well as to resist being charmed or paralyzed.

Sunlight Sensitivity. While in sunlight, the duergar has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.

Maddening Armor. When reduced below 20 hit points, Nildar Sunblight succombs to chardalyn-induced madness. At the starts of each turn, roll a d6 to determine his course of action:

• 5-6: he attacks hostile creatures;
• 3-4: he attacks allied creatures;
• 2: he wastes his turn swinging and shooting at the air;
• 1: he hits himself with a War Pick attack.

Multiattack. Nildar Sunblight makes two attacks with its War Pick or Javelin in any combination. Alternatively, Nildar uses Enlarge and makes an attack.

War Pick. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 12 (2d6 + 4) piercing damage, or 20 (4d6 + 4) piercing damage while enlarged.

Javelin. Melee or Ranged Weapon Attack: +4 to hit, reach 5 ft. or range 30/120 ft., one target. Hit: 9 (1d8 + 4) piercing damage, or 14 (2d8 + 4) piercing damage while enlarged.

Enlarge (Recharges after a Short or Long Rest). For 1 minute, the duergar magically increases in size, along with anything it is wearing or carrying. While enlarged, the duergar is Large, doubles its damage dice on Strength-based weapon attacks (included in the attacks), and makes Strength checks and Strength saving throws with advantage. If the duergar lacks the room to become Large, it attains the maximum size possible in the space available.

Invisibility (Recharges after a Short or Long Rest). The duergar magically turns invisible until it attacks, casts a spell, or uses its Enlarge, or until its concentration is broken, up to 1 hour (as if concentrating on a spell). Any equipment the duergar wears or carries is invisible with it.

Armored Blast. After hitting a creature with an attack, Nildar Sunblight can target one creature with the Fire Bolt cantrip.

Armored Bash. After hitting a creature with an attack, Nildar Sunblight can target one melee creature he can see. The target must succeed on a DC 13 Dexterity saving throw or be knocked prone.

Aggressive Metal.  When Nildar Sunblight is hit with an attack, its armor summons vicious flames around the attacker. The creature must make a Dexterity saving throw. It takes (2d10) fire damage on a failed save, or half as much damage on a successful one.