Aegislash

Stance Change. As an action, it can shift between two modes: Blade Forme and Shield Forme. Some actions force it into the other form, and it can't not take a form. While in Shield Forme, it has resistance to all damage except fire, and any attack triggers a bash reaction.

Sharpness. Whenever the Aegislash shifts from Shield Forme to Blade Forme, its next attack gains an extra 1d6 of its damage type. This bonus does not stack, nor does it affect attacks that force it from Shield Forme to Blade Forme.

Immutable Form. The Aegislash is immune to spells and effects that alter its form.

Metal form. The Aegislash is resistant to lightning damage and bludgeoning, piercing, and slashing damage from nonmagical weapons, and vulnerable to fire damage.

Cursed Weapon. A creature may attempt to grab the hilt of the sword, forcing the Aegislash to perform a DC15 dexterity save to avoid. If it fails, the Aegislash is considered grappled,  the ribbons wrap around the arm and, if the creature has an empty attunement slot, it forcibly attunes itself to the user. The user then picks up the shield and wields them both at once. The sword is a +3 enchanted shortsword and the shield is a +3 shield. If the Aegislash is killed, the blade and shield immediately rusts and withers, becoming unusable as equipment.

Soul Siphon. When a creature first attunes to the Aegislash, over the course of the next minute, it makes five attempts to siphon the soul from the wielder. Con save DC 18, 4d8 necrotic damage, or half that on a successful save. If the creature survives all five, then the Aegislash returns the soul and becomes loyal to the wielder. If the creature drops to 0 hit points at any point, their soul is consumed by the blade and the wielder drops dead.

Paired Beings. As long as the Aegislash is loyal to the wielder, it is a companion to them, using the same initiative count, and you can use your bonus action to command it. It will then complete the command to the best of its ability, then returns to your side. If you don't command it, it will largely do as it pleases, but it will prioritize protecting the wielder and attacking those hostile to it. You can revoke the attunement, but the Aegislash will continue to be loyal until the wielder clearly expresses they should part ways or is cruel to the Aegislash.

Multiattack. The creature can make three attacks during its turn in any combination of Punch, Bash, and Slash attacks, or one of its other actions.

Punch. Melee Unarmed attack: +3 to hit, range 5 ft., single target. Hit: 3 (1d4+1) bludgeoning damage.

Bash. Melee Improvised Weapon attack: +3 to hit,  range 5 ft., single target. Hit: 4 (1d6+1) Bludgeoning damage

Slash. Melee Weapon attack: +3 to hit, range 5 ft., single target. Hit: 9 (2d6+3) slashing damage.

Shield Toss. Ranged Weapon attack: +1 to hit, range 15/30 ft., single target. Hit: 6 (1d6+3) bludgeoning damage. Hit or miss, the shield returns to Aegislash.

Sacred Sword. Melee Weapon attack: +3 to hit, range 5 ft. radius, multi-target. Hit: 6 (1d6+3) slashing damage. Leaves a 10 ft. radius circle of mist where the action was performed that lasts for 3 rounds. Next time Aegislash shifts into Shield Forme, the mist explodes, forcing any creature aside from Aegislash in the mist to do a Dexterity save DC13. 1d8 force damage on a failure, half that on a success. (Performed in Shield Forme, ends action in Blade Forme)

Flash Cannon. Ranged Magic attack: 30 foot line. Creatures in range must make a Dexterity save DC13. 3d8 Force damage on a failure, half that on a success. (Performed in Shield Forme, ends action in Blade Forme)

Force darts. Ranged Magic attack: range 15/30 ft. Fires three darts, can target up to three creatures. Hit: 3 (1d4+1) Force damage. (Performed in Shield Forme. Ends in Shield Forme)

Shadow Sneak. Ranged Magic attack: range 30 ft. A shadow extends from the Aegislash's blade tip, zigzagging towards a creature it can see within range. At the start of that creature's turn, it must make a Dexterity save DC 13. 2d6 force damage on a failure, half that on a success. (Performed in Shield Forme, ends action in Blade Forme)

King's Shield. The Aegislash raises its shield, increasing its armor class by 10 until its next turn. If an attack would fall between its standard armor class and modified armor class, then it shifts into Shield Forme and emits a bright light in retaliation, dealing 10 radiant damage and forcing the attacker to make a Con save DC 15. The creature is blinded on a failed save. This reaction cannot be used if the Aegislash is in Shield forme. Recharge (4,5,6)

Parry. The Aegislash's armor class is raised by 5 until its next turn.