Living Weapon

You have an Unarmored AC of 14 + DEX modifier + STR modifier (Minimum 1) as the reactive metal conforms to block blows. It does not appear you are wearing armor unless you are hit by an attack or have taken damage within the last minute.

You can change your arms into five different non ranged simple weapons as a bonus action. You can have one arm in weapon mode at a time. You can switch which weapon is out twice per arm per long rest.

You have the weapon mastery feature for any Rivisium armament.

Your unarmed strikes deal 1D8 Piercing damage as you manifest spiked knuckles.

Rivisium armaments lose the Thrown property and are considered magical. You can change which weapons you can replicate during a long rest.

The Rivisium lends you its senses giving you Blindsight and Tremorsense 10 ft.

Your mastery of Rivisium leads to a breakthrough. You can change both of your arms into any non ranged simple weapons. You can have one of your arms become a shield as a bonus action and have the other one be able to be a weapon.

Your Rivisium body gives you a swimming, climbing, and crawling speed equal to your movement speed as your appendages optimize for you. Difficult terrain only reduces your speed by 5 ft.

You can change your arms into six different non ranged martial weapons in addition to your other forms. You can use an action to change each arm into a learned weapon that has the Light property. The weapons do not have to be the same one.

The Rivisium’s potential is further unlocked. Your skin can take on any one Armor Mastery property at a time. You can change the property during a long rest.

You have mastered a multitude of weapon forms. You can change your arms into any non ranged weapon.

The Revisium has grown to see you more than a simple host. When you are hit by an attack the Revisium makes an attack using a special reaction on its own. It shoots a tendril out with a range of 5 ft, + 9 to hit and deals 1D6 + 3 Slashing damage.

You have unlocked the full potential of Revisium. Any Rivisium armament becomes a +2 version of itself. You can change both of your arms into any one ranged weapon. The weapon fires bolts of energy, dealing Force damage in place of Bludgeoning, Piercing, or Slashing damage.

You can change your armaments as a free action once per turn.

You can use a reaction to manifest a shield giving you an extra 3 AC.

The Mizzium makes an attack once per turn using its Lashing Tendrils feature.