The Old Man is an unnamed antagonist from the Buffy episode "Homecoming". He did not engage in conflict personally but had the Gruenstalher Twins act on his behalf, using sophisticated technology to guide their actions: he was somewhat arrogant as well, believing that the other contestents were "idiots" or "in the past" while he was the "future".
Little is known of the Old Man's past, he is of British origin and acted as the superior to the German terrorist duo known as the Gruendstalher Twins: either unable or unwilling to engage in combat himself he instead acted as a guide to the twins and through them tried his hand at Mr. Trick's SlayerFest '98 challenge in which he tried to kill both Buffy Summers and Faith Lehane.
However the Old Man's dreams would come to an abrupt end when his two henchmen managed to accidentally shoot one another, leaving him without any means to continue the "game".
The ultimate fate of the Old Man is unknown but it is safe to assume he survived, though what he shall do without his henchmen to do his dirty work is not known.