
Note: If you crouch while Jack lunges horizontally with the chainsaw shears, you will unlock the "Duck if you love life" achievement. Swipe at Jack when you have openings, using the center pillar to avoid Jack's attacks. Use a combination of blocking and kicking those hanging corpses to avoid and stagger him. Jack will come at you with some bizarre chainsaw scissors.Press the reload button to rev the chainsaw back to life. If you overuse the chainsaw, the yellow light will turn red, and the chainsaw will stall. If you block at the last moment before being hit, Jack will stagger. Blocking with the chainsaw is very effective. Holding down aim and attacking does a lunging attack, and simply attacking does a swiping attack. The chainsaw is awkward to use but very powerful. After this, he will storm to one side of the arena and rip down part of the wall giving you access to the chainsaw. Once you've done enough damage, he will go down on one knee and begin to mutate.
