Rostam

Armor Infernal

Bonus Proficiencies

While bound to Rostam, you gain proficiency with heavy armor, as well as with flails and morningstars.

Mortal Bargain

While bound to Rostam, whenever you are reduced to 0 hit points but not killed outright, you remain conscious and don’t begin making death saving throws until the end of your next turn. If you take any damage while you have 0 hit points, you instantly fall unconscious and suffer one death saving throw failure.

Fiendish Resilience

Whenever you take bludgeoning, piercing, or slashing damage while wearing heavy armor, you can use your reaction to reduce the damage taken by 1d12. You can further reduce the damage by an additional 1d12 for each vestige other than Rostam you have bound. 
Once you use this feature, you can’t use it again until you finish a short or long rest.

Trait: Hideous Armor

While bound to Rostam, you can use your action to summon his hideous, infernal armor around yourself, along with any melee weapon of your choice with which you are proficient. The armor is a suit of plate that can’t be destroyed, and you can wear it without penalty, regardless of your Strength score. This equipment vanishes when you dismiss them as an action, or when you are no longer bound to Rostam.
The armor seems to be alive and is terrible to gaze upon. If you make a Charisma (Intimidation) check while wearing this armor, you can treat the result as a 10, or your binder level plus your Charisma modifier, whichever is higher.

Mythical armor of indescribable evil, Rostam will appear about his binders and shelter them from harm.

Legend

All the legends of Rostam the paladin tell of his seven great deeds in the demon land of Mazandaran, but a few make passing mention of his impregnable armor: black, stout, and indescribably hideous.
Rostam was a brave knight, to be sure, but he was no match for the demons of Mazandaran; he was not even a match for the deserts of that land. After a week of wandering aimlessly through the sands, Rostam was on the verge of death from dehydration when he came across a lone woman, a devil in disguise. She offered him a pact for his soul: she would give him food, water, and enough strength to slay the demons. Rostam readily accepted, and was bestowed a living suit of infernal armor: hideous, hairy, and indestructible. Guided by his infernal plate, Rostam went on to complete his seven deeds, and further to earn a reputation as a fearsome and savage warrior. Each new battle brought Rostam greater glories and new, terrible crimes. He slew every foe he met. One story even claims that he butchered his own son in a fit of rage. In his last and bloodiest battle, Rostam fell into a deep pit of spikes, which skewered him between the plates of the armor. Rostam himself bled to death, but the armor was not yet finished. It moved of its own accord, wading through the battlefield, slaying friend and foe alike, cackling with infernal cadence. 
Therefore, Rostam’s vestige is not the hero himself, but the hideous armor, which bleeds from every joint, the corpse of the so-called hero still within. 

Flaw

While bound to this vestige, you gain the following flaw: “Once I draw blood, I don’t stop fighting until my enemies are dead."