Shadow Knight

Tomb of the Shadow Knight
You meet him at the entrance of this quest. When you talk to him, he will reply:
 * Shadow Knight: Welcome to the tomb of my dreams and nightmares. Mdjai is underneath us, through this floor. I will remove it, but first, it is important you heed my warnings.
 * You: Ok. A little bit of darkness doesn't frighten me. Warn away.
 * Shadow Knight: Mdjai is warded by four altars of darkness. Purify them and you may slay the guardian. Be careful though. There is a fifth shadow, the Shadow Rogue. He is under my tutelage and set the protections in this place himself. The most obvious path will very rarely be the least dangerous one, but there is a relative term though. He is down there somewhere lurking also, be on your guard.
 * You: We shall be wary.
 * Shadow Knight: The altars are behind locked doors, so you'll need to acquire several keys. Remember, watch your step.