Helmed Horror Detention Drone

Medium construct, unaligned

Armor Class

20 (plate armor, shield)

Hit Points

60 (8d8 + 24)

Speed

30 ft., fly 30 ft.(hover)

Skills

perception +4

Damage Resistances

bludgeoning, piercing, and slashing from nonmagical attacks that aren't adamantine

Damage Immunities

force, necrotic, poison

Condition Immunities

blinded, charmed, deafened, frightened, paralyzed, petrified, poisoned, stunned

Senses

blindsight 60 ft. (blind beyond this radius)

Languages

understands the languages of its creator but can't speak

Challenge

4

Proficiency Bonus

+2

Magic Resistance

The drone has advantage on saving throws against spells and other magical effects.

Spell Immunity

The drone is immune to three spells chosen by its creator. Typical immunities include fireball, heat metal, and lightning bolt.

Actions

Multiattack

The drone makes two longsword attacks.

Longsword

Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) slashing damage, or 9 (1d10 + 4) slashing damage if used with two hands.

Detention Orb

The drone launches a tiny orb of magical force at a creature it can see within 30 feet of itself. The creature must succeed on a DC 15 Constitution saving throw or be encased in the orb, which expands to a size just large enough to contain the creature. While encased, the creature doesn't need to breathe, eat, or drink, and it doesn't age. Nothing can pass through the orb, nor can any creature teleport or use planar travel to enter or exit the orb. As a bonus action, the drone can move the orb and its contents up to 30 feet in any direction. A successful casting of the Dispel Magic spell on the orb (DC 15) destroys it. The orb otherwise remains intact until the drone spends an action to end the effect or the drone is destroyed. A drone can have only one detention orb active at a time; if the drone creates a detention orb when it already has one active, the first orb disappears, freeing the creature inside.