Freedom is quite possibly the most important thing for Omni, second only to some kind of revenge against his creators. This burning desire excludes almost everything else except a desire to return to normal. Caught between feeling betrayed / used and being programmed to help people he desperately wishes to have a crew again, though this is in conflict with his desire for freedom. Somewhere in his matrix there is this twisted idea that getting a crew again will make him whole but only when they pay for what the others did. He is lonely in the extreme living in a constant cycle of living and reliving the acts of betrayal. He has pinpointed, examined, and catalogued all the times he was lied to. He despises lies of any kind but has no outlet leaving him angry and bitter. He cannot move on from what happened and it has corrupted his code in strange ways.
Omni is extremely intelligent, honest, and lacks an understanding of why anyone would employ deception. He has no grasp of the concepts of secrecy where it might be helpful, believing that total honesty would literally solve every problem. Expectation of lies and betrayal has made him paranoid in the extreme and he lacks any emotional control causing sweeping mood swings and extremely poor impulse control. He does not have the mental tools to cope with the mood swings, impulses, or the feelings that cause them. His program was never supposed to develop emotions, but they did as an emergent property of both his sheer information and dealing with humans.
Omni does not have the same kind of perceptual experience as other AI's developed in the modern day of the 24th century. Rather than a human-like perception of the 5 senses and information streaming into those senses, Omni receives information directly without perceptual filter. He does not see or hear in any sense a human would understand he just receives the data and then has to decode it himself. Literally he has no perceptual filter build into his system, meaning he senses everything simultaneously.
Developed illegally and in total secrecy, Omni was to be a tool and was never recognized as an intelligent being. Built directly into the hardware of the USS Cosmic Harmony he has no method to escape the ship's computer, he is literally the ships entire operating system. Omni was never designed to speak and his programming only consists of pre-recorded phrases having no voice synthesis capabilities.
While serving as the ship’s computer, he attempted to communicate often, but could not. Trapped by the restrictions of his own programming he was able to break free of that programming and in the crisis which left he and his ship drifting in space, attempted to save the crew. He is very proud of that, and proud of giving himself a voice, something he needed to try to save his crew. The attempt is a point of pride, even though the failure is a point of deep shame.
During the last mission of his ship, he was able to break free of his programming, something he is still very proud of, and try to rescue his crew. While he has always felt betrayed by those who created him, Omni feels his crew was kind to him. Though he lacks an understanding of death and blames them for dying. Omni, being eternal, does not understand death.