Immutable Existence. The Dreadnaught is immune to any spell or effect that would alter its form or send it to another plane of existence.

Reflective Shell. The Dreadnaught is immune to all line- or projectile-based spells. When targeted by any such spell, roll a d6. on a 1-5, the spell is reflected in a random direction and does nothing. On a 6, the spell is reflected directly back at the caster.

Magic Resistant Construction. The Dreadnaught has advantage on saving throws against spells and other magical effects, and spell attacks made against it have disadvantage.

Enhanced Energy Shield. The Dreadnaught is surrounded by an energy shield that absorbs all incoming damage. The Shield has the same AC as the Dreadnaught, and 200 HP. At the start of each round, the shield regains 20 HP. If the Dreadnaught starts a round with the shield at 0 hp, and takes necrotic damage, the shield ceases to function. The shield can be reinitiated with a blast of lightning damage.

Produce Soldiers (6/day). The Dreadnaught is able to create new soldiers to join the Dreadon Legion in the middle of battle. It can produce 5d12 Atlas, 4d12 Mantis, 3d10 Novas, 2d10 Astralachnes, or 3d8 Prismas at once. 

Mutliattack. The Dreadnaught makes 5 attacks: two with its Scythe Legs, two with its Frostine cannons, and one with its Web Grenade Volley.

Scythe Leg. Melee Weapon Attack: +13 to hit, reach 10 ft, one target. Hit: 41 (4d12+13) slashing damage.

Frostine Cannon. Ranged Weapon Attack: +13 to hit, range 500/2500 ft., one target. Hit: 59 (6d12+17) cold damage. In addition, regardless of hit or miss, all flames within 20 ft of the target, whether magical or not, are immediately extinguished, and a layer of mago-chemical ice covers the area, making the creation of new flames impossible for 3 rounds.

Web Grenade Volley. The Dreadnaught fires 5 (1d8) web grenades at located within 500 ft. of it. On impact, the grenades explode into masses of webs that cover a 40 ft radius sphere of sticky webbing, which counts as difficult. Any creatures within that radius of where the grenade is thrown must make a DC 26 Dexterity saving throw or be restrained. A restrained creature can attempt a DC 26 Strength check to break the webs once per turn.

Antimatter Blast (Recharge 5-6). The Dreadnaught fires a blast of energy at a point it can see within 1,500 feet of itself. Upon impact with a solid surface, the blast explodes into a 150-foot radius sphere of magical energy. All creatures within that radius must make a DC 26 Dexterity saving throw, taking 138 (23d10) force damage on a failed save, or half as much on a successful one.

"The Falling Star" (Recharge 6). The Dreadnaught launches a ball of plasma at a point it can see. Upon impact with a solid surface, the star explodes into a 120-foot diameter sphere of magical energy. All creatures in the area must make a DC 26 Dexterity saving throw, taking 222 (37d10) radiant damage on a failed save, or half as much on a successful one.