The "faithful and discreet slave".
In Russell's day, and for sometime thereafter, the "faithful and discreet slave" was Russell by reason that he was in solely in charge, being viewed as God's channel. It was not a class of people.
Later the teaching of the "faithful and discreet slave" was changed a class of anointed JW's all around the earth.
Today the "faithful and discreet slave" is only the seven members of the governing body by reason that they are in charge, being viewed as God's channel.