Nathan Northwood. He loved reading comic books as a child and was surrounded by many superheroes. Even though he had no superpowers himself, that did not stop him from dreaming of becoming a superhero and forming his own team. He was.a child prodigy who worked hard in building gadgets and practicing combat moves. He eventually caught the eye of a High-tech company who saw much talent in him and had him work for them. He eventually proposed his plans to the company heads of forming his own superhero team and they allowed it.
Vanessa Von Lovejoy, a Demon Cat Seductress who was not as vicious and callous towards Humans as other demons. In fact, she truly wanted to spread love and joy, seeing them as showing much worth as partners. Nathan Northwood came across her while doing a "Secret covert mission" in a Strip club and convinced her to join him on his team.
Sebastian Armstrong, a loud and boastful Demigod who was born much stronger than his peers. He had no idea about his heritage as a Demigod until it was revealed to him later on. He went on a power trip and caused lots of property damage and injuries. Eventually Nathan Northwood arrived on the scene and was able to defeat him through sheer skill and trickery, taking him down a peg. He learned some humility and thus became an enthusiastic supporter of Nathan Northwood's team.
Richard Needlemeyer. He was born and raised in a Government lab for much of his life. He was the result of genetic engineering with his DNA tinkered with to make a very powerful Bio-weapon. He was treated like he was nothing but a machine whose only purpose was obeying the commands of his owners. Eventually he got sick of it and broke out, causing mass damage and causalities. He went on the run, rampaging across the country until Nathan Northwood and his team showed up to capture him. Sebastian Armstrong had hell of a time trying to take him down. Nathan Northwood was horrified when he found out about his origins. Eventually he made a point of taking him on not as a potential weapon but a teammate while trying to teach him how to be the person he never got a chance to be until now.
Hamilton Porkchops, a strange Alien with an incredible appetite. He and his race have the unique property of being able to harness the qualities of anything they consume. He went to Earth for something to eat. And ended up causing a commotion when he invaded an All-you-can-Eat Buffet and ended up eating everything. He then went on a rampage eating more stuff until Nathan Northwood tracked him down and tried to capture him. He was pretty amazed at seeing an alien like himself and decided to bring him aboard on his team. Though his eating habits do put bit of strain on their budget.
Gabrielle Ampersand. A vampire who did not want to drink the blood of humans like the rest of her clan whom she was estranged from. She was born with one of the strongest magics her family has seen but her refusal to drink blood seriously physically limited her. She had the unique magic of Transmutation in which she can transform all inorganic objects into another object as long as they both have the same mass. She can turn stone into Gold. Water into wine. She joined a Mystical society who taught her ways she can live among humans without feeding on blood. From there, she became a paranormal investigator who caught the eye of Nathan Northwood and offered her a job as part of his team which she accepted.
Juniper Sparkleboots, a fairy who came from a different realm of Fairyland. She and her kind love coming to Earth to mess with humans. She has the unique magic of being able to swap the locations of any two things provided they are the same size. She actually saw the Omega Patrol first before they saw her. They were on a different mission and she decided to mess with them. Eventually they managed to take her down despite her magics making it difficult to get close to her. She joined the team just to have some more fun.
Is this good enough, I dunno. You could change some things, it is hard trying to come up with unique characters.