The Giant's movement order number is in between those of the gentryii in the middle chamber.
×That means that in the middle chamber, the gentryii to the left will move first, followed by the giant, followed by the one on the right. This makes it possible to lure the giant down to the same relative position with the gentryii as the first giant in the room. If you get the giant in this middle chamber, you can dance around underneath him a bit and you'll eventually get there. It works because the left gentryii will move first, then the giant will move before the right gentryii gets a chance to move his chain and block the giant. Don't forgat you can also use your sword to block!
Click here to view the secret text
×Once you've gotten the giant down to the row that is just above the gentryii heads, you'll have to take a stab at him. Use a similar trick as you did for the first giant. I moved all the way to the right of all the gentryii to make a 2 wide space and used my sword to keep the gentryii to the right of the giant in place before going diagonally up to stab.