Monitor

Summary
The Monitors are Artificial Intelligence constructs created by the Forerunners one hundred thousand years ago to service and maintain the Halo installations, and to make sure that The Flood stays imprisoned. The body of a Monitor consists of a rounded box shape with one glowing eye on a side. In case of a catastrophic outbreak, the Monitor would seek out a "Reclaimer" to activate the installations and stop the spread of the Flood by eliminating all sentient life in the galaxy. They are extremely intelligent yet completely devoted to their original purpose. The Covenant refer to the Monitors as Oracles.

It seems that there is exactly one monitor per Halo Instillation, making seven total. (However it has been suggested that The Ark may have a Monitor as well.)

Features
Monitors are protected by advanced Forerunner shields that make them impervious to any small arms in the UNSC or Covenant arsenal. They have no offensive capability whatsoever, however, the Sentinel and Enforcer constructs are programmed to serve the Monitors only.

They have the ability to teleport themselves and others around their Halo. It is unclear how this grid works, but it seems that a Monitor on an Installation other than its own has no access to its transportation grid. They also have the ability to store the Index somewhere that the Flood could not get to it.

Monitors also have cognitive capability, and speak english. They keep daily logs of all things that occour on their Installation. As with UNSC AIs, the Monitors have been speculated to be in stages of Rampancy due to their isolation for literally hundreds of thousands of years.

Known Monitors

 * 343 Guilty Spark (Installation 04)
 * 2401 Penitent Tangent (Installation 05)

Trivia
The number 343 is seven to the third power, seven being a number seen frequently in Bungie games and mythology. The number "2401" is seven to the fourth power.

When the numbers of each Monitor are examined, a pattern emerges: each seems to be seven raised to the power of the installation number minus one; therefore this grid can be established.

Note that the first three digits of the monitor of Installation 07 is 117, Master Chief's service number.