Shadow Giant

Blacklight Strobe. The visual flicker of the shadow giant moving between the Material Plane and the Shadow Realm has a physical effect on viewers. A creature that starts its turn within 30 feet of the shadow giant and that can see it must succeed on a DC 18 Wisdom saving throw or be unable make more than one melee or ranged attack on its turn and unable to use bonus actions or reactions until the start of its next turn.

Distracting Flicker. A creature that starts its turn within 30 feet of the shadow giant and that is maintaining concentration on a spell must succeed on a DC 18 Constitution saving throw or lose concentration.

Shadow Sight. Magical darkness doesn't impede the shadow giant's darkvision.

Umbral Glimmer. At the end of each of the shadow giant's turns, it must roll a d20. On a roll of 11 or higher, it enters the Plane of

Shadow from the Material Plane. At the start of its next turn, it returns to the Material Plane in an unoccupied space of its choice that it can see within 40 feet of the space where it vanished. If no unoccupied space is available within that range, it appears in the nearest unoccupied space. While in the Plane of Shadow, the shadow giant can see and hear 120 feet into the Material

Plane. It can't affect or be affected by anything on the Material Plane while in the Plane of Shadow.

Multiattack. The shadow giant makes three attacks with its tenebrous talons.

Tenebrous Talons. Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 14 (2d6 + 7) slashing damage plus 18 (4d8) necrotic damage.

Cold Shadow (Recharge 5-6). The shadow giant directs its shadow to stretch out in a 60-foot cone. Each creature in that area must make a DC 18 Constitution saving throw. On a failure, a creature takes 52 (15d6) cold damage and has disadvantage on attack rolls and saving throws until the end of its next turn. On a success, a creature takes half the damage and doesn't have disadvantage.