Are the Childeren of the Dark Emperor aka Terrantos Diabolos Takahashi. He has Many children due to how many women he has (wives or Maidens). each of these women most like had have sex with the Dark Emperor leading to them giving birth to his children. The children of Terrantos are very powerful almost as powerful as the Titans or possibly stronger than Titans. Its unknown how powerful they are exactly but strong enough to defeat the Gods.
But some of the Children of Terrantos are not his Biological Children but Step-Children such as Mariko Kurama, while she is the daughter of Chief Kurama she is technically Lucy's daughter. Or Abe No Seimei or Crona Gorgon being step-Children of the Demon Emperor.
It is hinted the number of biological children he has reaches almost 90 or higher