HI BEN

On the Halo 2 campaign level "Regret", there is an easter egg with the words "HI BEN" written on the ceiling of a hidden room that is dedicated to Benjamin Burnley of Breaking Benjamin, who wrote a song that appears in Halo 2.There is also, in purple, the "rock on" hand sign on the right hand corner.

Process
You will need:
 * A Sniper Rifle or Beam Rifle
 * The Sputnik skull

Start the level Regret and proceed until you kill the Drones and Elites. Go outside and to your right you will see a temple with a broken bridge leading to it. Grenade jump there and go to the room to your right. Activate your flashlight and go to a left corner and zoom in with your scope and you will see the message.