"That he had that power long before he ever came here. We think we cannot change things. We are wrong. We do not lack for power, or influence, or money. All we ever miss... is the moment of decision. At the end, he had his moment. At the end... What else is there?" -- Miguel (Spider Society Mague).
Ezekiel is a man with the power of an arachnid, much like Spider-Man. Ezekiel's powers were given to him during an arcane ritual he was forced to take part in while exploring Central America. He wanted the powers in order to become a hero, but he believed that he needed a base of operations from which to do that. Thus, he went into business, using his powers for personal gain. During this time he lost sight of his original objective and became too busy in his work to do any good. Eventually, Ezekiel tracked Peter Parker down in New York, where they fought against Morlun together. Ezekiel tried to convince Peter that he knew why so many supernatural beings were after him. He claimed it was because they did not believe that Peter 'deserved' his powers, and that he was chosen by the Spider wishing to pass the powers on before he died. At the end of the final battle with Morlun, which Ezekiel barely survived, he vowed to begin using his powers for good.
The Book of Ezekiel
During this story arc, Ezekiel went back to visit Peter in New York, claiming it's to help him get rid of the supernatural beings that are attacking him. However, his true motive was to attract the Pretender to Peter and to get him to attack Spider-Man instead. It turns out that the supernatural beings were actually trying to kill Ezekiel, as he was the one who did not deserve his powers. The Pretender easily defeated Peter, knocking him unconscious. When he awoke he was in South America being beaten on by Ezekiel. Peter then became tied to a pillar, and Ezekiel spilled some of Peter's blood into a spider-shaped crevice in the floor. This attracts a giant spider come to kill Peter, mistaking him for Ezekiel. Ezekiel walks off, but at the last minute has a change of heart, realizing that Peter could do more good with his powers. Ezekiel attracts the spider's attention by kicking it and has his life taken instead. Peter passes out from the pain, but when he wakes up he is helped by Miguel, the very man who helped Ezekiel receive his powers. Miguel tells Peter that he is Spider-Man, because he is meant to be, and there are no contradictions.
Ezekiel was mysteriously brought back to life but only as an animated corpse covered in spiders. He seems to have been sent back to the world of the living to inform and help Spider-Man and other spider powered individuals as the Kravinoffs begin hunting them but this was shortly revealed to have been Chameleon luring Spider-Man into a trap at the hands of the Kravinoffs.
Ezekiel possesses a number of superhuman attributes that are almost identical to those naturally possessed by Spider-Man. His strength, speed, stamina, agility, reaction time, and resistance to physical injury are all enhanced to superhuman levels. Although Ezekiel is of an advanced age, none of his physical attributes have declined over the decades.
Ezekiel also possesses the ability to stick to most surfaces and crawl along them in the same way as Spider-Man. He also possesses a type of forwarning, that serves as an early warning system in much the same way as Spider-Man's spider-sense, although his wasn't as developed as Spider-Man's. Because of their nearly identical powers, Ezekiel and Spider-Man are immune to each other's early warning system.
In addition to his powers, Ezekiel is extremely wealthy and is a highly skilled businessman and owner of a company with international connections. As with Spider-Man, he is a formidable hand to hand combatant though he's had no formal training. He uses a type of unique freestyle of fighting that allows him to make full use of his powers. He also has some knowledge of the mystical nature of totems.