ok, first load a map with no people in HL2 (like the beginning of Black Mesa East, where youre outside next to water, or garrys mod construct.) Next I'm going to have you spawn a gman somewhere, anywhere quiet and empty. To spawn a gman, look at the ground where you would like to see him appear, go into the console, and type "npc_create npc_gman" without " ". exit console and look at your creation, making sure your crosshairs are on him, now go into console again and type in "ent_setname bob", you now have named this gman bob, cool. But thats not it, god no, that would be pointless..... After that type "ent_fire bob setexpressionoverride scenes/citadel/al_end" (big one, I know).....now hit enter and exit console for a wonderful suprise....the gman will speak as though he was alyx at the end of the game, then, at the end of the speach, well...just watch his face. Enjoy......