Overlord

Overlord is the code name of an American command base that during combat gives information on enemy strength and location, as well as new orders or objectives to soldiers in action.

Call of Duty 4: Modern Warfare
Overlord was the U.S. Command from Call of Duty 4: Modern Warfare during the U.S. Marine invasion of Al-Asad's country (labeled "Command" in the subtitles, identifying himself as "Overlook" at the beginning of Shock and Awe). He was last heard on the mission "Shock and Awe" after the nuke exploded.

Call of Duty: Modern Warfare 2
Overlord gives orders to the US Army Rangers, particularly Hunter Two-One, in Call of Duty: Modern Warfare 2. He is heard in "Of Their Own Accord", "Wolverines!" and many other levels.

Call of Duty: Modern Warfare 3
Overlord also appears again in Call of Duty: Modern Warfare 3 giving orders to the Delta Force. He is the Survival Mode announcer. He is also the announcer for Delta Force in multiplayer. During the cutscene of "Iron Lady", his information and his connecting with the Presidential Aide ranks him as a General Commander.

Trivia

 * Overlord was originally the voice of the U.S. Army Rangers multiplayer announcer in Call of Duty: Modern Warfare 2, and can be heard announcing the AC-130 in the "Customized Killstreaks" trailer.
 * Overlord appears in and survives all games in the Modern Warfare series, along with Price and Nikolai.
 * His callsign in Modern Warfare 3 is "Centcom Comm".
 * Overlord was heard at the end of Hostage Taker, saying "Good job team".
 * In Modern Warfare 3, Overlord is almost always heard in Special Ops, as in the mission Milehigh Jack the announcer talking to the player is Vladimir Makarov.