C'tan Shard of Entropy

Saves: Toughness +15, Willpower +14

Senses: Perceives the age, wear, and remaining span of everything within 120 feet

Field of Decay. Everything within 30 feet of the shard wears out: at the end of each round, cover in the field degrades one step and each creature inside takes a cumulative -1 Defense as armor pits and straps rot (restored only by repairs). A creature that rolls a natural 1 on an attack inside the field has its weapon jam or crumble.

Nothing Lasts. At the start of each of its turns, the shard regains 20 Vitality as its wounds themselves decay closed - unless it took damage from at least two different damage types since its last turn. Only sustained, varied pressure accumulates against it.

Preserved Anchor. This is the objective: things outside time's reach - stasis fields, Necron seals, the one preservation relic the mission put in the party's hands - resist its decay entirely and can cage it. Luring or sealing it into a stasis anchor is the only permanent defeat; reduced to 0 Vitality otherwise, it disperses and resumes elsewhere, patient as erosion.

Age to Dust. Melee Attack: +14 to hit, reach 10 ft., one target. Hit: 5d10 + 7 rending damage as flesh and gear age decades in a heartbeat, and one piece of the target's equipment is permanently ruined unless the target makes a Toughness Save DC 20.

Rot the Ground. The shard decays a 30-foot zone within 90 feet: floors weaken, cover crumbles to nothing, and the zone becomes hazardous ruin - difficult terrain that deals 1d10 rending damage to creatures ending their turn in it.

Entropic Exhalation. The shard breathes decay in a 30-foot cone. Creatures in the cone make a Toughness Save DC 20, taking 5d10 rending damage on a failure or half on a success; on a failure their speed is halved until the end of their next turn as joints and sinews age, and one piece of their equipment degrades.

Decay the Blow. When a weapon attack hits the shard, the weapon used suffers a cumulative -1 to hit until repaired, as the strike costs the blade or barrel years of its life.

Morale: Does not make Morale checks. It is patient the way erosion is patient, and it retreats from nothing except preservation itself.

Tactics: Give the encounter a stasis-anchor objective - seals to activate, a preservation field to lure it into - and let the decay aura tax every round of hesitation. The party's gear sheet is the damage track: rifles fail, armor sloughs, cover expires. Speed and decisiveness are the counters; a siege against Entropy is a siege it has already won.

Loot / Evidence / Hooks: The stasis anchor that holds it is worth more than the world it was saving - and the shard inside is still owed time.

The C'tan Shard of Entropy is the heat-death of the universe running ahead of schedule: armor rusts, walls sag, flesh ages, and plans decay in its presence. It does not destroy things; it forecloses on them.

Use this threat when the party's equipment, cover, and time itself should become consumable resources — a fight against decay with a face.

Boss-grade threat, continuous armor and gear degradation, cover erosion, aging attacks, objective-based defeat, punishes slow methodical play.

Field of Decay. Everything near it wears out: cover degrades each round, weapons risk jamming, and armor sheds Defense that only repairs can restore.

Nothing Lasts. Immune to lasting harm from any single source; wounds close as the damage itself decays. Only sustained, varied pressure or containment mechanisms accumulate against it.

Preserved Anchor. Objects outside time's reach — stasis fields, Necron seals, one relic the mission gave the party — resist it and can cage it.

Age to Dust. Touches a creature or object: accelerated entropy deals heavy damage and permanently ruins one piece of equipment; Toughness Save resists.

Rot the Ground. Decays a zone of terrain: floors weaken, cover crumbles, and the area becomes hazardous ruin.

Entropic Exhalation. Cone of temporal decay: damage, gear degradation, and slowed movement as joints and sinews age.

Morale: No morale; it is patient the way erosion is patient, and it retreats from nothing except preservation itself.

Tactics: Give the encounter a stasis-anchor objective — seals to activate, a preservation field to lure it into — and let the decay aura tax every round of hesitation. The party's gear sheet is the damage track: rifles fail, armor sloughs, cover expires. Speed and decisiveness are the counters; a siege against Entropy is a siege it has already won.

Full Stat Block Priority: Boss