Omega Sentinel is immense -- immensely strong, immensely logical, and immensely powerful. Once sent to Earth to locate the missing Omega Supreme, the Omega Sentinel was found instead by the Decepticons, and lent his awesome firepower to their cause. Megatron described him as a cross between Shockwave's mind and Devastator's power. Although not as ambitious as Shockwave, the Omega Sentinel was also loyal only to his sense of logic, and would switch allegiences at a moment's notice if his analysis dictated it. The Omega Sentinel's deep devotion to logic made dealing with the highly emotional human populace of Earth difficult at times. Fortunately, as a Decepticon, the Sentinel could simply destroy anything that struck him as illogical and be done with it.
Dreamwave comics continuity
The Omega Sentinel was apparently sent out into space some time ago, searching for Omega Supreme. He eventually found the planet Earth, but was taken in by the Decepticons before he could locate Omega Supreme. Through persuasion or reprogramming, Megatron succeeded in bringing the Omega Sentinel in line with the Decepticon cause. He planned on using the giant as a secret weapon against the Autobots at a later date, but those plans were dropped once Megatron was kidnapped by the Keepers and Starscream assumed command of the Decepticons. Starscream activated the Omega Sentinel and brought him to the new Decepticon capitol, Las Vegas. Omega Sentinel was present in Vegas when Megatron returned from space with the Keepers in tow. Although he was too badly injured to retake command of the Decepticons by force, Megatron nevertheless refused to serve under Starscream, and several Decepticons made the same choice. The loss of the Omega Sentinel was one of the most crushing blows to Starscream's command, but the Sentinel did not find Starscream logical, and so threw in with Megatron. The renegade Decepticons made an alliance with the Autobots against the Keepers, and returned to Las Vegas to annihilate the aliens after they executed Starscream and bestowed his corpse on one of their own as a host body. The Omega Sentinel planned to personally obliterate the Keeper-Starscream in battle, but he and Devastator were held back from the final conflict by an energy field generated by the Keepers. Worse still, this meant they were too far away from Optimus Prime when he used the power of the Matrix to defend all the other Autobots and Decepticons present from a nuclear blast, launched at the Keepers by the US military. Having absorbed the brunt of the radioactive fire, Omega Sentinel was rendered totally inoperative and unsalvagable.
- The Omega Sentinel's appearance is unknown. Presumably, he looks like the typical "Guardian Robot" design used for Omega Supreme and other generic Guardians. He is first described as black and gold, but later as blue and red, the latter being the traditional colors of the Guardians.