The Z Syndicate (ZX Syndicate in Japan) is a sinister and mysterious organization and is one of the antagonists in Custom Robo (GameCube). General knowledge about them is scarce to the public and their motives are truly difficult to pin down. However what is known is that they're constructing plots through use of Custom Robo. The heads of the Z Syndicate include Oboro, Eliza, Isabella, and Sergei. Oboro and Sergei work together while Eliza and Isabella are a team. Sergei was the sole member of the Z Syndicate that remained loyal to the Hero's Father, the original leader.