Possessed Pillar

Construct Nature. The possessed pillar doesn't require air, food, drink, or sleep.

Divine Fists. The possessed pillar's weapon attacks are magical. When the pillar hits with a Slam attack, the Slam deals an extra 2d8 necrotic damage or radiant damage (included in the attack), the pillar's choice.

False Appearance. While the pillar remains motionless, it is indistinguishable from a statue or a carved column.

Immutable Form. The pillar is immune to any spell or effect that would alter its form.

Magic Resistance. The pillar has advantage on saving throws against spells and other magical effects.

Magnetic Body. The eldritch magic powering the possessed pillar causes the pillar's body to produce a minor magnetic field. When a creature hits the pillar with a weapon made of metal, it must succeed on a DC 15 Strength saving throw or the weapon sticks to the pillar. If the creature can't or won't let go of the weapon, it is also stuck to the pillar and restrained. A stuck weapon can't be used. A creature can take its action to remove one metal object from the pillar by succeeding on a DC 15 Strength check. The pillar can release one creature or metal object stuck to it as a bonus action. If the pillar dies, all creatures and metal objects stuck to it are released.

Multiattack. The possessed pillar makes two Slam attacks.

Slam. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 14 (2d8 + 5) bludgeoning damage plus 9 (2d8) necrotic damage or radiant damage (the pillar's choice).