Well-dressed and powerful entities with reality-bending powers and an often calm demeanor working under higher beings (The Employers and Lord English), that make it their job to facilitate the forthcoming of important events in their stories (With Scratch, it's the creation of the Green Sun, his own creation, and the arrival of his Lord. With the G-Man, it was the destruction of Black Mesa, the Resonance Cascade, which also led to the Combine invasion, and more). Both can be rather manipulative, and used the main protagonists as pawns to further their own interests, with one in particular being a young girl they seem to have had an interest in for a while (Rose Lalonde and Alyx Vance). Both have notoriously used their powers to manipulate time and teleport people and themselves into other locations.

Might rework on the connections sooner or later, but here they are at their current state. Man how much I wish G-Man actually fought though