Loners

Loners are characters who keep to themself. They may work with a team but they usually with themselves

Zero: He works alone for the most part due to being the one who harbors the Maverick Virus which turns programs Maverick. 

Lizbeth, while she tries to get her friends to work together and be in teams. She plays solo more than anyone, due to a sub conscious fear that being associated her leads to death or disaster

Venus: She was sent to help her parents in the past, but works alone to prove that she can take care of herself.