Thornheart Guardian

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

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

Magic Weapons. The thornheart guardian's weapon attacks are magical

Woodland Walk. Difficult terrain composed of nonmagical plants doesn't cost the thornheart guardian extra movement. In addition, the thornheart guardian can pass through nonmagical plants without being slowed by them and without taking damage from them if they have thorns, spines, or a similar hazard.

Multiattack. The thornheart guardian makes three attacks: two with its barbed greatsword and one with its thorny whip.

Barbed Greatsword. Melee Weapon Attack: +8 to hit, reach 5 ft, one target. Hit: 13 (2d8 + 4) slashing damage plus 7 (2d6) piercing damage.

Thorny Whip. Melee Weapon Attack: +8 to hit, reach 15 ft., one target. Hit: 11 (2d6 + 4) piercing damage, and the target is grappled (escape DC 16) if it is a Medium or smaller creature. Until this grapple ends, the target is restrained, the guardian can automatically hit the target with its thorny whip, and the guardian can't make thorny whip attacks against other targets.

Grasp of the Briar (Recharge 5-6). The thornheart guardian summons grasping, thorny vines to impede and drain the life of its foes. The ground within 20 feet of the thornheart guardian becomes difficult terrain for 1 minute. This difficult terrain doesn't cost the thornheart guardian extra movement. A creature that enters or starts its turn in the area must succeed on a DC 16 Strength saving throw or be restrained by the plants. A restrained creature takes 7 (2d6) necrotic damage at the start of each of its turns. A creature, including the restrained target, can take its action to break the target free of the vines by succeeding on a DC 16 Strength check.