Liam is an American voice actor and voice director perhaps best known for his roles as Gaara of the Sand in Naruto, War in the video game Darksiders, Captain Jushiro Ukitake in Bleach, Vincent Law in Ergo Proxy and Illidan Stormrage in the Warcraft game series - World of Warcraft: The Burning Crusade.
He is married to fellow voice actress Amy Kincaid and is also one of the English adaptation writers for the popular series, Naruto.
O'Brien is usually cast in some of the most unusual roles, as such he tends to play characters that show signs of insanity or are complete evil geniuses. Some of those include: Gaara from Naruto, Lloyd from Code Geass, Isaac from Castlevania: Curse Of Darkness, Lezard from Valkyrie Profile 2, Grimoire Weiss from Nier, Kain from Final Fantasy IV, and Dist from Tales of the Abyss.
He's been honored with a nomination for "Best Voice Actor in an Anime Comedy" by the American Anime Awards for his work in Comic Party, DNA Squared, and Girls Bravo.