Onyx Sentinel
From Halopedia, the Halo wiki
The Onyx Sentinel is Forerunner-created electromechanical variable configuration and purpose machine. It is exclusive to the Forerunner artificial world known as Onyx.
Appearance
The Onyx Sentinel shares a similar appearance to the Monitors - with a round sphere in the center, and with a central "eye" that glows golden. The eye is the cut-down Energy Projector. However, it also has three metal booms extending from equistidant points on the surface of the central sphere.
The Onyx Sentinel also has antigravity technology, not unlike the Covenant. Although the Onyx Sentinel can even reach escape velocity and fly into outer space, in ground operations, it normally engages its targets at a height of three meters.
Combat
It is extremely versatile, and is a powerful combatant on both the ground and in space. One of their primary advantages is a gold-colored Energy Shield that is completely resistant to all projectiles, even the rockets of the Rocket Launcher and LOTUS Mine detonations. However,the shield is fouled by slow moving objects, such as a rock, which was used to destroy one Sentinel on Onyx. It is also very adaptive, each Sentinel transmitting its combat footage to an unknown intelligence that continually upgrades Onyx Sentinel combat algorithms. as per a Spartan: "We are teaching it how to fight".
It is far superior to the regular Sentinels that guard the Halo ring-installations, and even the Sentinel Majors and Enforcers, due to its shielding and extreme firepower: a cut-down Energy Projector firing golden, lethal spears of light. A single impact causes devastating damage; the destruction of a granite plateau, vaporization of a combat bunker, and the instantaneous destruction of any ground vehicle or infantryman, including even a SPARTAN-III. Enough Sentinels can even vaporize a large starship.
