Kernwill was a Federation Vice admiral in service in the late 24th century.
He was the Starfleet Command contact to Commander Sisko during a crisis between the Klingon Empire and the Cardassian Union in 2370.
He was the one to assign Ambassador Berel to conduct the negotiations between the feuding powers. Ultimately he would order Sisko to handle the negotiations after Berel's death. (DS9 - Hearts and Minds comics: "For the Glory of the Empire", "On the Edge of Armageddon")