In Halo 2, Lord Hood is a UNSC Admiral. On board Cairo Station, he gives Sergeant Johnson the Colonial Cross for "acts of singular daring and devotion", as well as Miranda Keyes a posthumous award for Captain Keyes.
He has a very high rank in the UNSC. In Halo: First Strike, he was part of an ONI council that included General Strauss and Colonel Ackerson. In Halo 2, he was sufficiently well-placed to override Fleet Admiral Harper's orders.
He was the one made to say the erroneous "fleet at Reach was fifty times this size" comment.
After Outskirts, he is not seen or heard from again until the final cutscene of The Great Journey, where he is seen alone on the damaged Cairo.