Master Khan is a sorcerer who has fought Iron Fist and Namor.
He created a lengthy and complicated scheme to get revenge on Iron Fist involving much subterfuge. First he brought the Super-Skrull to Earth. At the time, the Super Skrull had been converted to pure radiation and existed in Earth's orbit; he was dying of a disease. Khan brought him down and promised to heal his desease if he worked for Khan. The Super-Skrull agreed. Khan then transformed him into Captain Hero (a child, Bobby Wright, that could turn into a hero, somewhat like Billy Batson and Captain Marvel), and erased his memories so that he forgot his alien origin. Khan also created multiple fake identities for himself, including Bobby Wright's guardian and Tyrone King, a police officer. In his guise as King, he had an affair with Misty Knight; she was unaware of his true identity until years later. Captain Hero then had a lengthy storyline in which he befriended Iron Fist, and ultimately killed him.
However, the Iron Fist that Captain Hero killed was actually not Iron Fist, it was a H'ylthri plant construct; they were working on their own scheme relating to Iron Fist at the same time.
Later, during a H'ylthri invasion of Earth, Master Khan intervened and destroyed a great mass of H'ylthri at once using his magic. He then used his powers to remove the memories of Namor (who was present at the time), an effect which worked for 6 months.
That storyline later involved Dr. Doom. When Doom eventually escaped a trap of Khan's, Doom defeated him with his own magic.
Powers and Abilities
Master Khan seems to be a sorcerer of medium power. He was capable of teleporting himself and others, of removing people's memories, of transforming the Super-Skrull from radiation into his body again, and apparently giving the Super Skrull, in his guise as Captain Hero, powers beyond his normal power set, such as intangibility. He could conjure the Crimson Bands of Cytorrak.