Anaxim

Memories of the Gods. The anaxim has advantage on History (Intelligence) checks that involve gods.

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

Legendary Resistance (3/Day). If the anaxim fails a saving throw, it can choose to succeed instead.

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

Magic Weapons. The anaxim's attacks are magical.

Expeditious Shifting. If the anaxim uses more than half of its movement, it gains a +2 bonus to AC until the start of its next turn.

Unstable End. The anaxim explodes immediately if it reaches 0 hit points. The explosion destroys the anaxim, leaving its body behind in pieces. Each creature within 25 feet of the exploding anaxim must make a DC 22 Dexterity saving throw, taking 52 (15d6) bludgeoning damage on a failed save, or half as much damage on a successful one. On a failed save, a creature is also deafened for 1 minute.

Whirling Blades. Any creature that starts its turn within 5 feet of the anaxim takes 18 (4d8) slashing damage.

Multiattack. The anaxim uses either its shrapnel blast or its sonic screech, if available. It then makes four attacks: one with its scythe arm, two with its spinning blades, and one with its unerring slam. It can make one cannon attack in place of its unerring slam.

Unerring Slam. Melee Weapon Attack: +17 to hit, reach 5 ft, one target. Hit: 76 (12d10 + 10) bludgeoning damage, and if the target is huge or smaller, it is pushed up to 5 feet away from the anaxim.

Scythe Arm. Melee Weapon Attack: +17 to hit, reach 10 ft, one target. Hit: 40 (12d4 + 10) slashing damage. When the anaxim attacks a creature that has at least one head with this weapon and rolls a 20 on the attack roll, the anaxim cuts off one of the creature's heads. The creature dies if it can't live without its head. A creature is immune to this effect if it is immune to slashing damage, doesn't have or need a head, or has legendary actions. Such a creature instead takes an extra 27 (6d8) force damage.

Spinning Blades. Melee Weapon Attack: +13 to hit, reach 5 ft, all targets within reach. Hit: 24 (4d8 + 6) slashing damage.

Cannon. Each creature in a 10-foot radius sphere centered on a point within 60 feet of the anaxim must make a DC 22 Dexterity saving throw. A target takes 44 (8d10) force damage on a failed save, or half as much damage on a successful one.

Shrapnel Blast (Recharge 3-6). The anaxim jettisons a spray of jagged metal in a 30-foot cone. Each creature in the area must make a DC 22 Dexterity saving throw, taking 52 (8d12) peircing damage on a failed save, or half as much damage on a successful one.

Sonic Screech (Recharge 5-6). Loud screeching of metal and steel emanates from the anaxim. Each creature within 60 feet of the anaxim must make a DC 22 Constitution saving throw, taking 90 (20d8) thunder damage on a failed save, or half as much damage on a successful one. On a failed save, a creature is also stunned until the end of the anaxim's next turn.

Adamantine Armor. If the anaxim is subjected to a critical hit from any weapon not made out of adamantine, it can use its reaction to make that attack automatically miss instead.

Jagged Exterior. If a creature misses the anaxim with an attack of opportunity, the anaxim can use its reacion to make that creature take 16 (4d4+6) slashing damage.

The anaxim can take 3 legendary actions, choosing from the options below. Only one legendary action can be used at a time, and only at the end of another creature's turn. The anaxim regains spent legendary actions at the start of its turn.

Move. The anaxim moves up to half its speed without provoking opportunity attacks.

Recharge (Costs 2 Actions). The anaxim rolls to recharge its shrapnel blast or its sonic screech.

Repair (Costs 2 Actions). The anaxim regains 50 hit points.

Summon Iron Golem (Costs 3 Actions). The anaxim summons 1 iron golem within 5 feet of it.