Renor Drokk Zalkri (also known as Black Fist Zalkri) is a mechanical arm (left) forged by an exiled Halruuan wizard named  Beld'ar Costello Indolour, in a time before the Paradox Kilmaruu and the Shadow elf siege existed. 
   It was said that Indolour was banished for collaborating with the dark elves, which was partly true (according to magical inquisition). He travelled north, over seas and plains and highlands. He met different cultures, and he adapted to their ways. It was said that he had a companion that is of drow origin (perhaps half-drow), who bore a mechanical arm that slowed down his actions, and thus, was called by the northmen as the "crippled crow." Indolour, seeing that his friend might one day die because of this handicap, cast a potent enchantment on the metallic appendage. The arm began to feel lighter and felt like a normal arm, and as an offensive bonus, a succesful strike (as in a punch) is succeeded by a Level 6 Blackfist spell, which is often the leading cause of death for "the crow's" adversaries. 

This weapon was first "tested" on the Ruathen Hamfarrigen, wherein Indolour and his small band won without much effort. The Ruathen First Axe, Zalkri Borgumm, was the first to be slain by the weapon, which led to the unusually easy victory. Enthralled by the event, Indolour named the weapon "Renor Drokk Zalkri" in honor of his dark elven friend and of the brave shapestrong berserker Zalkri. 

 From the elf known only as the "Crippled Crow", the arm was taken as a part of the Rashemi hoard, after Indolour and his party waged war against the Rashemen Berserkers. All other supplies and equipment were taken by the Rashemen, the magical ones taken personally by the Withces themselves. The rest (including the arm) were used by the Berserkers on their campaigns in the north. For 400 years, they never found out how to use the arm properly, so it was merely put in their warehouses until it was stolen and fenced by a foreign thief in the markets of Luska, where it was purchased by a weapon collector known as Selenith Durd'arra. 

Selenith held the weapon for nearly three years, after which her manor was pillaged by gnolls, led by elven sorceress Quenall'ine Morgana. Morgana found out about the weapon thru rumors and written history, and she sought out to retrieve such lost artifacts. The arm she later handed over to her right-hand, Kazz Mathgonn. It was when she and her  'mechanized' gnoll army trekked to undermountain that she met Chazmyr Hun'ett, a drow wizard who is in the service of the god Vhaeraun. Chazmyr had foreseen their arrival thru the scrying bowl, and had prepared for battle well. His uncanny allies (human and elf at that)ambushed the gnolls from the side, while Kazz Mathgonn and  Morgana were slaughtered by Chazmyr. Chazmyr lost his left arm in the battle, but was quick to replace it with the mechanical arm, which, with a few adjustments, suited him perfectly.  
 

Abilities
Upon a succesful hit(melee), the weapon causes 1d8+2 damage to target, which is automatically succeeded by a 2x3x4 ft big Black Fist (Level 6) which causes damage which is equivalent to the damage caused by a Black fist spell cast at a similar level(in our sessions, its damage is 1d20+6+strentgh modifications). Target must save versus wand at -2 to receive at least half damage, and a critical hit is equivalent to a crushing blow (usually crushes armor, doubles damage, and results to death if save fails. A succesful save renders the target unconscious for 1d10 rounds + the half damage, depending on the dm's discretion). Every succesful hit throws the enemy (dead or alive)1d8 feet backwards or sidewards, depending on the angle of impact. The Black Fist effect cannot be repeated until after two turns, when the gauntlet section has been fully recharged.

It serves as a shield+1 (consider buckler) in most cases, and it can also support shields, provided that the bearer CAN carry that shield.  

In order to use the weapon, you should have one arm less (preferrably left. Drow don't have problems with limb-lopping, since the clergy of Lolth  and most mages can regenerate limbs). Only elves and other races and individuals of similar stature may use the weapon, provided that they have a REALLY good explanation on how they acquired it. Good characters tend not to possess weapons of evil such as this, but it's okay if the dungeon master himself allows it to happen.