This man, whose identity is unknown, is the Overseer of the New Jersey Chapter of The Order. According to his speech in Greg's Log #3, this particular Overseer was appointed to his position of power by Jacob Rainwood, the current Chief Overseer.
The Overseer was first seen in Greg's Log #3, in which he welcomes Greg Benson into The Order. He is seen once more in the TribeTwelve video titled The Order, in which he is "interviewed" by Noah Maxwell at the Atlantic Test Site. During said interview, the Overseer, along with many other members of The Order that were present, kneeled in respect for the Slender Man when it arrived and seemingly transported a member of the organization to the 4th World.
As the Slender Man proceeded to assault many of The Order's members, the Overseer's status temporarily remained unknown. However, he was later confirmed to be alive in Log Entry #28, in which he leads the execution of Jesse Laurenzi, a Vassal who had broken several of The Order's laws.