Dimension Transfer: G-Man covers the players screen in a green overlay and teleports them to a Half-Life dimension or if that's too much you just teleport around the map.

Timestop: G-Man stops time and makes a speech before erasing nearby entities and dissapearing.

Judgement: G-Man crumbles reality deleting the map and leaving nothing but a black void, this annihilates every entity and player before the map is reset.