Pillar of light
A Pillar of Light is found in Night-Gazer Khighorahk's room. Lighting them reduces his defence. When the Night-Gazer's special attack is used the light might go out and you can take damage if too close when it goes out. You will take some undefendable damage if the torch goes out and you are within 2 squares of it. In the second stage of killing the boss, the torch will go out less often, therefor making a solo dungeon easier to complete.
If you are in a team, a good way to take down the Night-Gazer Khinghorahk is to have 1-2 people (depending on the team size) constanly relighting the torches, and have the rest of the team attacking the boss. Remember, the torches only lower the Night-Gazer's defence, it doesn't make your attacks useless.