Can't get to the Mirror Knight (Dark Souls 2)

castle drangelic: after defeating the two riders should fire further down the passage, there seems to be a lift, but its only a hole in the ground: to the left like there is a lever, but he did not pressed - not even the actions button
on the right staircase, climbed up on it - there's a room with a statue of a giant and petrified knights - scheme like the former, the soul knights have to fill the bowls of the statues of giants, BUT the knights did not want to live, just sit in the stones and all.
in General, guys what to do?