Who is the man with red eyes in A Wrinkle In Time? What is he trying to do to the children?

The man with the red eyes is the Prime Coordinator for IT, the machine mind that controls the people of Camazotz. He has a soothing voice as he interacts with the children in the Central Central building, but his intentions are evil. He wants to infiltrate the children's minds and control their brains so that they function in sync with the computerized IT.
If he is successful, this will dehumanize the children and rob them of their will and individuality, as well as their emotions of kindness and compassion. Charles Wallace takes the risk of looking into the man's red eyes to try to understand who he is, and he is taken over by IT. The red-eyed man's goal is to similarly gain control of Meg and Calvin.