Outskirts Energy Sword

The Outskirts Energy Sword is an Easter egg found in the Halo 2 Campaign level Outskirts. It is an Energy Sword wedged into a stone in reference to Excalibur, and it can be found near the Rex Egg.

Directions
To reach the sword, one must get to the Rooftops vacation; this can be accomplished at the very start of the level. As soon as you exit the room with the crashed Pelican, jump onto the door frame. From there, jump onto the higher platform. Make your way over the rooftops to the sword; it is in the top level of a building not far from Hotel Zanzibar. The building's roof has a large chunk missing, suggesting something hit it.

Note that if you have not already killed all of the enemies at the Hotel, obtaining this Sword will prompt an Ultra Elite to attack it.

Trivia

 * The Rex Easter egg does not always appear; sometimes, when it does appear, the Energy Sword has infinite charge.