Shade

   The man who became shade was once a normal human.  Serving a lengthy sentence for dealing cocaine, he noticed his cellmate (Richard Cranston, in jail for murder) was obsessed with occult spells.  Curious, he began to eavesdrop and even went so far as to look over Cranston's notes.  One day, Cranston managed to find a private place and drew a pentagram.  He then chanted some spells, branded a star shaped mark on his neck, and knelt down as a glow began to creep around him.  His cellmate then appeared from the shadows knocked Cranston out of the pentagram with a large wooden bored.  He then branded the same star insignia on his neck and jumped into circle himself.  He began to fade into the astral plane, and Cranston jumped into the portal trying to follow him.  He did not gain any powers, but his sudden entry into the mystical world gave him knowledge of several cosmic things and was subsequently mentally shattered.  His cellmate became the Shade; able to turn himself intangible, teleport, enter the astral plane, gain incredible strength, and never tire.  
     Shade soon learned he had made a terrible mistake.  Jumping into the portal unplanned like that had forced him to spend most of his time in the astral plane.  To stay in Earth, he had to teleport people into the astral plane.  Shade then returned to the criminal underworld, and began to take teenagers addicted to drugs.  The teenagers often were trying to quit, and had thus gained the wrath of the gangs.  Since they were poor, unreliable, and often homeless they were not greatly missed.  
     Shade first encountered Spider-man after taking a homeless youth who had recently quit cocaine.  Spider-man attacked him, but Shade gained the upper hand in the fight, and then faded into the astral plane.  Spider-man had, however, noticed the odd insignia on Shade's neck.  With the help of a police liutenant, Spider-man located the only person in the system with such a marking recorded--Cranston.  Despite being severely troubled and institutionalized, Cranston told Spider-man the entire story.  With the help of Doctor Strange, Spider-man briefly entered astral form.  He then followed Shade through a portal and found all the missing people.  Shade battled him in the astral plane, and was gaining the upper hand when Spidey threw him into the large cocoon that he had thrown the people.  The cocoon exploded (the people had broken out with Spidey's help).  Spidey brought everyone to New York, but said he doubted Shade was really dead.