C'tan Shard of the Broken Sun

Saves: Toughness +15, Willpower +13

Senses: Perceives everything within its corona; nothing inside the light is hidden from it

Corona of Ruin. A 60-foot radius around the shard is a standing hazard: creatures that start their turn inside take 2d10 fire damage, cover inside warps and degrades one step per round, and moving while exposed sears - +1d10 fire damage for each 20 feet moved without cover.

Uncontained Output. At the start of each round after the first, the corona's radius grows by 10 feet or its start-of-turn damage increases by 1d10, GM's choice. The encounter has a countdown whether the party engages or not.

Fractured Core. This is the objective and the way in: every third round the corona collapses inward for one round, dropping the hazard entirely. Only during a collapse can containment anchors be planted against its surface or the binding device fired. Reduced to 0 Vitality without containment, it detonates and re-condenses in the crater.

Solar Lash. The shard whips an arc of stellar plasma along a 120-foot line, 10 feet wide. Creatures in the line make an Agility Save DC 20, taking 6d10 fire damage on a failure or half on a success. Cover in the line ignites, and creatures who fail take a further -1 Defense as their armor slags until repaired.

Nova Pulse (Recharge 5-6). The shard detonates. Every creature in the corona makes a Toughness Save DC 20, taking 8d10 fire damage on a failure or half on a success. Unattended cover in the corona is destroyed.

Gravity of a Dead Star. Every creature and loose wreck within 60 feet makes an Agility Save DC 20 or is dragged 20 feet toward the shard. Creatures dragged adjacent to it take 3d10 fire damage and learn why nothing stands at the center.

Flare Rebuke. When a creature hits the shard with a melee attack, the attacker takes 2d10 fire damage from the backwash.

Morale: Does not make Morale checks. It is an explosion negotiating with its own containment, and it always votes for release.

Tactics: Structure the fight in pulses: approach during core-collapse windows, shelter through the nova cycles, and plant the anchors or fire the impossible weapon before the corona outgrows the map. Standing damage makes loitering lethal and geometry sacred. This is a campaign-tier objective encounter - the party wins by ending it, not outlasting it.

Loot / Evidence / Hooks: The crater-glass and irradiated necrodermis flakes left after binding are priceless to the Mechanicus and lethal to carry.

The C'tan Shard of the Broken Sun is the memory of a murdered star wearing necrodermis, radiating destruction it can no longer entirely aim. It does not have attacks so much as weather.

Use this threat when a region — not a room — is the encounter: an irradiated crater-zone with a furious god at the center and survival as the opening objective.

Boss-grade threat, battlefield-scale radiation and heat, catastrophic area attacks, terrain destruction, objective-based defeat, survival-timer pressure.

Corona of Ruin. A radius around it is a standing hazard: escalating heat and radiation damage, warping cover, and searing exposed movement.

Uncontained Output. Each round its damage radius or intensity grows; the encounter has a countdown whether the party engages or not.

Fractured Core. Its own instability is the way in: at intervals its corona collapses inward for one round, opening a window to approach, strike, or plant the containment device.

Solar Lash. Arc of stellar plasma across a line: heavy damage, cover ignition, and armor degradation.

Nova Pulse. Detonation centered on itself, devastating everything in the corona; Toughness Save for half. Recharge.

Gravity of a Dead Star. Drags creatures and wreckage toward it; those who reach the center learn why nothing stands there.

Morale: No morale; it is an explosion negotiating with its own containment, and it always votes for release.

Tactics: Structure the fight in pulses: approach during core-collapse windows, shelter through the nova cycles, and place anchors or fire the impossible weapon before the corona outgrows the map. Standing damage should make loitering lethal and geometry sacred. This is a campaign-tier objective encounter — the party wins by ending it, not by outlasting it.

Full Stat Block Priority: Boss