Sepulcher Knight of Harrowvane

Traits

• Magic Resistance. The knight has advantage on saving throws against spells and other magical effects.
• Oathbound Revenant. The knight swore to hold Harrowvane's gate and was buried beneath it. If reduced to 0 hit points within 1 mile of its own grave-marker, the knight crumbles to ash and reforms there at dawn with half its hit points, unless the marker has been unmade by a wish spell or by a living heir of Harrowvane speaking the knight's true name over it.
• Marshal Undead. Undead creatures of the knight's choosing within 60 feet of it cannot be turned while the knight is conscious, and they add the knight's Charisma modifier (+4) to their saving throws against effects that would destroy or banish them.

Spellcasting

Its spellcasting ability is Charisma (spell save DC 17, +9 to hit with spell attacks).

• Level 1. Command, Hellish Rebuke
• Level 2. Darkness
• Level 3. Dispel Magic
• Level 4. Blight

Actions

• Multiattack. The knight makes three Longsword attacks.
• Longsword. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 3d10 + 5 slashing damage. The blade drinks what it cuts. The target takes an extra 9 (2d8) necrotic damage, and its hit point maximum is reduced by that amount until it finishes a long rest.
• Hellfire Orb (Recharges after a Long Rest). Hit: 10d6 fire damage. The target must succeed on a DC 17 Dexterity saving throw, taking half as much damage on a successful one. The knight hurls a guttering sphere of grave-fire to a point it can see within 120 feet, where it erupts in a 20-foot-radius sphere.

Bonus Actions

• Grave Step. The knight sinks into the ground and rises from a patch of consecrated or grave-turned earth it can see within 30 feet, leaving a scatter of cold ash behind. It cannot use this ability while grappled or restrained.

Reactions

• Parry. The knight adds 4 to its AC against that attack, potentially causing it to miss. To do so, the knight must be wielding a melee weapon.

Legendary Actions

• Sword Stroke.
• Grave Wind. A cold wind smelling of turned earth sweeps out from the knight. Each creature within 15 feet must succeed on a DC 17 Constitution saving throw or have its speed halved until the end of its next turn.
• Rally the Fallen. The knight raises its broken banner. Up to three undead of CR 5 or lower within 60 feet that can see it may immediately move up to their speed and make one weapon attack as a reaction.

Lair Actions

• Gate That Will Not Open. Every door, portcullis, and grate within the cathedral slams and seals. Until the next lair action, opening any of them requires a successful DC 17 Strength (Athletics) check made as an action.
• Roll of the Dead. The names of Harrowvane's fallen garrison are spoken from the walls in a dry chorus. Each non-undead creature that can hear them must succeed on a DC 17 Wisdom saving throw or be frightened of the knight until the end of its next turn.

Regional Effects

• No Bell Will Ring. Within 1 mile of Harrowvane, bells, horns, and other alarms produce no sound. Spells and abilities that rely on an audible signal at range fail unless cast at 5th level or higher.
• The Ground Remembers Its Dead. Corpses left on open ground within 1 mile of the cathedral sink beneath the soil overnight and cannot be recovered by nonmagical means. A creature that finishes a long rest in this area gains no benefit from it unless it rests on consecrated stone.