Mourning Sentinel

Kneel, Be Still Or Be Remembered

“I pass beneath your watch and remain unbroken, not by chance, but because you have judged me and found no cause to act. That is a gift I do not take lightly, nor will I forget who granted it.”
— Corvyn Seinrill
The Mourning Sentinel is not a guardian in the crude or immediate sense of the word. It does not patrol, it does not pursue, and it does not hunt. It exists as part of the tomb itself, a presence embedded so completely into the architecture and ritual of the space that it is difficult, at first, to distinguish it from the structure it inhabits. Those who enter its chamber often mistake it for a monument, a carefully carved funerary figure adorned with gold veining and deliberate symmetry, a work meant to honor the dead rather than defend them.   That impression does not last.   The first movement is slow and deliberate, not violent, not reactive, but intentional in a way that immediately alters the understanding of the room. A head turning where no movement should exist, a shift in posture that reveals the figure was never truly inert. The silence that follows is not empty, but occupied, as though the chamber itself has become aware of those who have entered it. This is the moment when the Sentinel begins its work, and that work is not immediate destruction.   It is judgment.   The Mourning Sentinel evaluates before it acts, and that evaluation is based not on presence alone, but on conduct. It observes the way intruders move through the space, how they speak, what they touch, and whether they treat the tomb as a place of rest or as an obstacle to be overcome. These observations are not passive. They carry weight, and that weight manifests in subtle but undeniable ways. Movement becomes more difficult, as though the air itself resists urgency or disrespect. The simple act of crossing the chamber without care can provoke a response, not out of anger, but as a correction imposed by something that does not tolerate irreverence within its domain.   When the Sentinel does act, it does so with a force that feels less like aggression and more like inevitability. Its strikes are heavy, deliberate, and grounded, each motion carrying the weight of the stone from which it is formed. There is no wasted movement, no flourish, only impact delivered with a certainty that suggests the outcome was decided before the blow was ever struck. Those caught in its grasp experience something beyond physical restraint, a pressure that extends into thought itself, compelling stillness and suppressing resistance in a way that feels imposed rather than earned.   The environment does not remain passive during this. The chamber responds in concert with the Sentinel, as passages narrow, surfaces shift, and familiar paths become obstructed. What was once open space becomes difficult terrain, and what appeared stable reveals itself to be subject to change. This is not random alteration, but alignment, the structure of the tomb reinforcing the purpose of the being that inhabits it. Movement becomes constrained not only by the Sentinel’s presence, but by the space itself, which no longer behaves as a neutral setting.   As the encounter progresses, the Sentinel’s presence deepens rather than escalates in any conventional sense. It does not become enraged, but more pronounced, more certain in its role, until the moment comes when its outer form can no longer sustain the force acting within it. When its marble shell fractures, the transition is not a collapse into weakness, but a revelation of what was always present beneath the surface. The exposed form, dark and inscribed with countless names, shifts the nature of the encounter from physical opposition to something more unsettling and more personal.   At this stage, the Sentinel’s purpose becomes explicit. It no longer merely reacts to behavior. It demands acknowledgment. Those within its presence are compelled to define themselves, not through force, but through declaration. Name, purpose, truth. These are not requests offered as options, but conditions imposed by a being that does not recognize anonymity or silence as valid responses. To refuse is not to resist, but to diminish, as the Sentinel ceases to treat the individual as something distinct.   This is where the encounter changes from a test of strength to something more difficult to resolve.   Because the Mourning Sentinel is not defeated in the traditional sense. It can be damaged, restrained, even temporarily broken, but its purpose does not end through force alone. It exists to measure and to preserve, and the only way to conclude its judgment is to engage with that purpose directly. Acts of reverence, admission, and sacrifice are not mechanical solutions, but meaningful responses that align with the function it was created to uphold. Each act has a cumulative effect, reducing its capacity to act not by weakening it physically, but by satisfying the condition it exists to enforce.   When that condition is met, the Sentinel ceases its hostility without resistance. It does not fall in defeat, nor does it retreat. It simply returns to stillness, reassuming its place as part of the tomb, as though the interruption of its purpose has been resolved and no further action is required. The chamber settles with it, the shifting stone returning to its original state, the oppressive presence lifting just enough to allow movement without resistance.   What remains is not victory in any conventional sense, but acknowledgment.   The Mourning Sentinel does not guard treasure, nor does it protect the dead from harm in the way one might expect. It ensures that those who enter its domain are measured against the weight of what lies within, and that they do not leave unchanged by that measure. Whether that change is recognized in the moment or only understood later is of no concern to it.   Its purpose is fulfilled the moment judgment is passed.
“I have cataloged ruins that crumble at a touch, and relics that whisper when disturbed. This thing did neither. It simply watched, and in that watching, I understood that I was the one being uncovered.”
— Wayland Whitesteel, retired archaeomancer
Genetic Ancestor(s)
The Seinrill Catacombs
Plot | Feb 14, 2026

Your Legacy Awaits


Unknown Shores

Mourning Sentinel CR: 12

Huge construct, lawful neutral
Armor Class: 19
Hit Points: 210 (20d12 + 80) 20d12+80
Speed: 30 ft

STR

22 +6

DEX

8 -1

CON

18 +4

INT

10 +0

WIS

16 +3

CHA

14 +2

Saving Throws: Con +9, Wis +8
Damage Resistances: bludgeoning, piercing, and slashing from nonmagical attacks
Damage Immunities: poison, psychic
Condition Immunities: charmed, frightened, paralyzed, exhaustion
Senses: darkvision 120 ft., passive Perception 13
Languages: understands the languages of its creators, communicates telepathically
Challenge Rating: 12 ( 8,400 XP)

Sanctified Weight. Creatures within 10 feet of the Sentinel treat the area as difficult terrain. A creature that takes the Dash action or otherwise moves recklessly within this area takes 10 (3d6) radiant damage.   Etiquette Binding. A creature is considered irreverent if it speaks loudly, disturbs or damages a tomb, removes objects from a sarcophagus, or uses mocking or dismissive language toward the dead. An irreverent creature has disadvantage on saving throws against the Sentinel’s abilities until the end of its next turn. The DM may rule additional actions as irreverent if they violate the sanctity of the space.   Ledger of Passing. At the start of the encounter, the Sentinel senses acts of violence committed by the party within the last 24 hours or since their last long rest. Acts of mercy prolong its initial stillness. Neutral conduct produces no effect. Acts of cruelty or unnecessary slaughter cause the Sentinel to begin in a heightened state of judgment or grant it advantage on its first attack roll.   Judged Priority. The Mourning Sentinel instinctively targets the creature it perceives as most irreverent. The DM may determine this based on player actions or track it informally. If multiple creatures are equally irreverent, the Sentinel chooses the one closest to it.

Actions

Multiattack. The Sentinel makes two Buttress Slam attacks.   Buttress Slam. Melee Weapon Attack +10 to hit, reach 10 ft., one target.
Hit 19 (3d8 + 6) bludgeoning damage. If the target is pushed into a solid surface, it takes an additional 10 (3d6) bludgeoning damage.   Funerary Grasp. Melee Weapon Attack +10 to hit, reach 10 ft., one target. Hit The target is grappled (escape DC 17), restrained, and takes 10 (3d6) psychic damage at the start of each of its turns.   Dirge Resonance (Recharge 5–6). The Sentinel emits a low resonant hum in a 30 foot radius. Each creature must make a DC 17 Constitution saving throw. On a failure, a creature takes 27 (6d8) radiant damage and its speed becomes 0 as it is compelled to kneel in involuntary reverence. On a success, the creature takes half as much damage.

Bonus Actions

Grave Alignment. The Sentinel reshapes the chamber’s geometry. Until the start of its next turn, it creates one of the following effects.   A 5 to 10 foot passage between sarcophagi is sealed
Stone slabs rise to grant the Sentinel half cover
A clear path becomes difficult terrain

Reactions

Grave Rebuke. When a creature behaves irreverently, the Sentinel makes one Buttress Slam attack against that creature. The target must succeed on a DC 16 Wisdom saving throw or be unable to speak until the end of its next turn.  

Phase Two: The Inner Tomb

When the Sentinel is reduced to half its hit points, its outer marble shell fractures and collapses away.   Beneath it is revealed a darker form of black basalt, its surface carved with thousands of names. The chamber fills with layered whispers.  You will be remembererd.”   For a moment, the echoes of the chamber fail to repeat one character’s voice.   Litany of the Interred (Recharge 4–6)
The Sentinel targets one creature it can perceive.   The target must use its turn to speak its name, purpose, or a meaningful truth aloud.   If it does so, it gains advantage on its next attack roll or saving throw.   If it does not, it has disadvantage on all attack rolls and saving throws until the end of its turn and takes 10 (3d6) psychic damage.   If the target fails to respond for two consecutive rounds, the Sentinel no longer acknowledges them as an individual. Attack rolls against that creature have advantage until it successfully speaks its identity.   Sepulcher Collapse (1 per encounter)
The Sentinel strikes the ground, fracturing the chamber.   Each creature within 20 feet must make a DC 17 Dexterity saving throw, taking 18 (4d8) bludgeoning damage and falling prone on a failure, or half as much damage on a success.   The affected area becomes difficult terrain.  

Weakness: Rite of Acknowledgment

A creature may use its action to perform a meaningful act of reverence.
  The effect escalates with each use.   First use. A simple respectful gesture or minor offering causes the Sentinel to lose its reaction until the end of its next turn.   Second use. A sincere apology, personal truth, or meaningful act causes the Sentinel to lose its next action.   Third use. A significant personal sacrifice causes the Sentinel to immediately cease all hostile actions and return to its dormant form, ending the encounter.   Further attempts have no effect.   Any item offered is absorbed into the Sentinel’s chest cavity and cannot be recovered.

Usual Tactics

Do not rush this encounter. Allow silence between descriptions. Let players speak over each other, hesitate, or correct themselves. The Mourning Sentinel is most effective when the players feel they are being observed, not attacked.

A towering marble figure carved like a sealed tomb slowly turns its head toward you, gold veining shifting across its body as if something beneath the stone has just begun to notice you.

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