Zeke is actually a pedophile for having molested little girls, so he was placed in a trap to teach him to let go of the things that had allowed him to "touch" others.
Michael finds Zeke stuck to the celing in a room full of bombs, the door closes to keep michael from escaping and Billy tells Michael that he will have to hury or he and Zeke will both die. Michael frees Zeke and shuts off the bombs, but Zeke's hands are torn off as he is freed and he passes out from shock and blood loss. Pighead 2 later finds Zeke and drags his unconcisious body away. Zeke is healed by Jigsaw and Pighead 2, who tell him his game is over and he can go home. Zeke, blaming Michael for the loss of his hands however, decides to stay so he can kill Michael, cut his hands off and use them to replace his old ones (even though he needed to lose his hands to live, and it was really all Jigsaw's fault).
Zeke has his hands replaced with blades, and he begins chasing Michael around trying to kill him. Zeke attacks Michael twice in the game, first in a chasing level (where michael manages to escape) and later on in a boss battle (where Michael lurs him into a trap and kills him).
Zeke is shown to be highly insane during his boss fight frequently yelling "Im gonna pop you like a balloon of blood" "I want my hands back, mabye ill take yours" "slice slice slice" "youll look better in pieces" "look now all I need are these (refering to his blades)" and "Im gonna cut you open and crawl on you like a cat", which hints that he went insane after his test.