Borland of Dzughan

 Immutable Form. Borland is immune to any spell or effect that would alter its form.

Dense Soul. Borland has advantage on saving throws against spells, other magical effects and is resistant to magical attacks.

Multiattack. The golem makes three corrosive blade attacks.

Corrosive Blade. Melee Weapon Attack: +17 to hit, reach 10 ft., one target. Hit: 19 (3d10 + 7) slashing damage with bonus 10 (2d8 + 4) acid damage.

Toxic Cloud. Borland release a toxic breath, that burns the lungs and noses of creature that got hit. Creatures 5 ft. around the main target must make DC 20 wisdom saving throw, taking 22  (3d12 + 8) poison damage. The cloud stays for 2 turn, dealing as much damage every turn and they also cant heal or be healed while inside. Only take half as much damage on a successful one.

Ensnare. Borland throw a heavy rusty metal chain that could wrap around and hold a target in its place. Creature must make a DC 20 dexterity saving throw or be restrained for 1 turn.

Decompose. Borland constantly regenerating and decomposing at the same time, releasing dangerous gas that could slowly kill any living being near him. Creatures within 5 ft. of him takes 4 (2d4 + 1) poison damage. The damage gradually increases as his hp got lower, getting another 6 (2d6 + 2) bonus damage when he is below 400 hp. Decompose increased by 5 ft. and get another 10 (2d8 + 4) extra bonus damage when below 150 hp.

Borland can take 2 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn. Borland regains spent legendary actions at the start of its turn.

Toxic Cloud (Costs 3 Actions). Borland uses Toxic Cloud.

Ensnare (Costs 2 Actions). Borland uses Ensnare.