Magic Weapons. The golem's weapon attacks are magical.
Invocation. The golem can be summoned by the creator, it appears in a free space within 30 feet of its creator in its medium form, it can bring up to two other willing creatures with it that are within 30 feet.
Telepathic Channel. The golem can telepathically communicate with the creator at any distance, there is a 5% chance of failure if they are on a different plane.
Regeneration. The shield guardian regains 15 hit points at the start of its turn if it has at least 1 hit point.
Antimagic Field. The golem was constructed with a core that feeds on magical energy, creating a 10-foot radius of antimagic around it. Additionally, any spell that is cast within or enters the radius heals the golem for a number of hit points equal to the level of the spell slot used.
Size change. The golem can change his size, between Medium, Large and Huge.
Multiattack. The golem makes three melee attacks.
Slam. Melee Weapon Attack: +14 to hit, one target. Hit: 23 (3d8 + 8) [bludgeoning] damage.
Grapple. The target must be no more than one size larger than the golem and must be within reach. Using at least one free hand, the golem attempts to grapple the target by making a grapple check instead of an attack roll: a Strength (Athletics) check contested by the target's Strength (Athletics) or Dexterity (Acrobatics) check (the target chooses ability to use). If successful, the target is subject to the grappled and restrained condition.
Brutal Throw. The golem takes any creature it has grappled and tosses them up to 30 ft. away. If the creature comes into contact with another target, both creatures must succeed on DC 18 Dexterity saving throws or take 12 (3d6) bludgeoning damage and be knocked prone.
Counterspell. The golem can cast counterspells as if it were its creator using its status for any ability check effects.
Channel Magic. The creator can use the golem to cast a spell through it.