This is an idea I've had for a while, but I never took the time to iron out all the details.
The Black Savaran
Real name: Nasir Garrett
Age: 17
Height: 5'9"
Weight: 140 lbs.
Relatives: Fereshteh Jalali (mother), Nathan Garrett (father, deceased), Dane Whitman (cousin)
History: Persian-British son of Nathan Garrett, the villainous Black Knight. His mother had a brief tryst with Garrett in England, but they parted ways before either of them realized she was pregnant. By the time Nasir was born, Garrett had already embarked on a life of crime, so Fereshteh hid Nasir's father's identity from him. At the age of 15, she finally told Nasir about his heritage, and afterwards he was magically drawn to Garrett Castle, Dane Whitman's ancestral home in England. Once there, he was compelled to touch the Ebony Blade, which triggered his latent mutant ability to absorb the properties of things he touches. Unfortunately, the Ebony Blade's powerful magic locked his power so that he could only mimic its properties.
Dane Whitman found Nasir trapped in his ebony body. He felt responsible, both because Nasir was a relative and because Dane knew what it was like to have the Blade tear his life apart. Through his mixture of scientific and mystical knowledge, Dane was able to partially unlock Nasir's power, enabling him to return to human form, at least. He could still only transform into the Ebony Blade-like body when he used his power, though. During their search for a cure, Dane and Nasir became friends. Nasir was so taken by Dane's stories of superheroics and adventure that when he was cured, he asked Dane to train him and Dane agreed.
After gaining a high degree of skill in swordsmanship and the martial arts, Nasir heard of the American Young Avengers. Still aching to follow in his cousin's footsteps as a hero, he created a costume combining elements of his Persian and Black Knight heritages and set out to join the Young Avengers as the Black Savaran.
Powers: Nasir's mutant ability would have been to absorb the properties of anything he touched, but the Ebony Blade magically locked this ability to its own abilities. As such, Nasir can turn his body into the same material that the Ebony Blade is composed of. Like the Blade, he is virtually indestructible, and he is also able to absorb and redirect energy.
Weapons: Nasir wields a shamshir forged by the legendary 17th-century swordsmith Assadullah, given to him by Dane Whitman as a birthday present.