Castrum Omicron

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

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

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

Siege Monster. The castrum deals double damage to objects and structures.

Fragile Limbs. The castrum’s four limbs individually have an HP bar (exactly 400 HP each). Upon defeating a limb, the castrum takes 200 damage (the HP lost can not be restored by any means unless under repair) and is restrained and incapacitated for 2 rounds. During this time, all attacks dealt upon the castrum will deal twice the damage. Each limb is vulnerable to all attack types (except the types in which the castrum is immune to), but they are also immune to all conditions. The hind limbs can only be broken during the charging time for Castellum Impulsum, while the front limbs can not be broken during that time. If the hind legs are broken, instead of 2 rounds, it will be restrained and incapacitated for 4 rounds.

Multiattack. The castrum makes 2 melee attacks and 2 ranged attacks.

Blazing Arrow. Melee Weapon Attack: +17 to hit, reach 14 ft., one target. Hit: 2d10 + 10 piercing damage and 1d4 fire damage.

Ballistic Impact. Ranged Spell Attack: +17 to hit, range 14/140 ft., one target and all targets near 5 ft. of target. Hit: 2d10 + 10 fire damage.

Castellum Impulsum. Melee Weapon Attack: +18 to hit, reach 10 ft., one target. Hit: 5d10 + 100 bludgeon damage. This attack needs 3 turns before hitting the target. During that time, the target is restrained, and the castrum is incapacitated and also restrained. The attack will be interrupted once a hind limb is broken, and the damage will be halved once both front limbs are broken.