Kryx RPGThemesMonsters

Hellfire Engine

Huge construct
16 (15,000 XP)


Defense note natural armor
Damage resistances cold, psychic; bludgeoning, piercing, and slashing from nonmagical attacks that aren’t silvered
Damage immunities fire, poison
Condition immunities charmed, deafened, exhausted, frightened, paralyzed, poisoned, unconscious

Speed 12 m.
Senses darkvision 35 m.
Languages understands Infernal but can’t speak

Immutable Form. The hellfire engine is immune to any spell or effect that would alter its form.

Magic Resistance. The hellfire engine has advantage on saving throws against spells and other magical effects.

Maneuvers. The hellfire engine uses maneuvers (maneuver save DC 18). It has 45 stamina dice which are d8s, a dice limit of 5, regains all expended stamina dice when it finishes a long rest and regains half its total stamina dice (rounded up) when it finishes a short rest, and knows the following maneuvers:

1 stamina die: debilitating crush, disorient, glancing blow, hammer spin, hammer through, hammering blow, knockback, spring attack, sturdy stance

2 stamina dice: stone bones, tremoring strike


Flesh-Crushing Stride. The hellfire engine moves up to its speed in a straight line. During this move, it can enter Large or smaller creatures’ spaces. A creature whose space the hellfire engine enters must make a DC 18 Reflex saving throw. On a successful save, the creature is pushed to the nearest space out of the hellfire engine’s path. On a failed save, the creature falls prone and takes 28 (8d6) bludgeoning damage.

If the hellfire engine remains in the prone creature’s space, the creature is also restrained until it’s no longer in the same space as the hellfire engine. While restrained in this way, the creature, or another creature within 1.5 meters of it, can make a DC 18 Strength check. On a success, the creature is shunted to an unoccupied space of its choice within 1.5 meters of the hellfire engine and is no longer restrained.

Hellfire Weapons. The hellfire engine uses one of the following options:

If the chosen option kills a creature, the creature’s soul rises from the River Styx as a lemure in Avernus in 1d4 hours. If the creature isn’t revived before then, only a wish spell or killing the lemure and casting true resurrection on the creature’s original body can restore it to life. Constructs and devils are immune to this effect.

Bonemelt Sprayer. The hellfire engine spews acidic flame in a 18-meters cone. Each creature in the cone must make a DC 20 Reflex saving throw, taking 11 (2d10) fire damage plus 18 (4d8) acid damage on a failed save, or half as much damage on a successful one. Creatures that fail the saving throw are drenched in burning acid and take 5 (1d10) fire damage plus 9 (2d8) acid damage at the end of their turns. An affected creature or another creature within 1.5 meters of it can take an action to scrape off the burning fuel.

Lightning Flail. Melee Weapon Attack: +10 to hit, reach 3 m. Hit: 18 (3d8 + 5) bludgeoning damage, or 21 (3d10 + 5) bludgeoning damage if used with two hands, plus 22 (5d8) lightning damage. Up to three other creatures of the hellfire engine’s choice that it can see within 9 meters of the target must each make a DC 20 Reflex saving throw, taking 22 (5d8) lightning damage on a failed save, or half as much damage on a successful one.

Thunder Cannon. The hellfire engine targets a point within 35 meters of it that it can see. Each creature within 9 meters of that point must make a DC 20 Reflex saving throw, taking 27 (5d10) bludgeoning damage plus 13 (2d12) concussion damage on a failed save, or half as much damage on a successful one.