Spectral Guardian (5e Creature)
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Large undead, neutral
Skills Perception +5
Incorporeal Movement. The spectral guardian can move through other creatures and objects as if they were difficult terrain. It takes 5 (1d10) force damage if it ends its turn inside an object.
Magic Resistance. The spectral guardian has advantage on saving throws against spells and other magical effects.
Magic Weapons. The spectral guardian's weapon attacks are magical.
Multiattack. The spectral guardian makes two attacks with its claws.
Claw. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 15 (3d6 + 5) force damage.
Harrowing Roar (Recharge 6). The spectral guardian emits a magical roar. Each creature of the spectral guardian's choice within 60 feet of it that is able to hear the roar must make a DC 15 Wisdom saving throw or take 33 (6d10) psychic damage and be frightened for 1 minute. A creature that succeeds on its saving throw takes half as much damage and isn't frightened. An affected creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
Powerful magic can trap a soul inside an object and give it purpose and a vague physical form, not unlike that of a cloud of whitish-blue dust or smoke. Such creatures are called spectral guardians, and they are bound to those objects, hiding within them, potentially indefinitely, until a predetermined trigger is activated or command word is spoken. When such an occasion occurs, the glowing cloud bursts out and performs the activity that was programmed into it. For example, a spectral guardian within a knocker might invite guests into a noble manor, or drive off unwanted riffraff, while one within the gem-encrusted sarcophagus of an ancient wizard would attack any who enter his burial chambers. When spectral guardians attack, they lash out with claws that seem to be made from fog, or roar with a mind-rending energy that inspires great fear in those that hear it.
Undead Nature. A spectral guardian doesn't require air, food, drink, or sleep.