Board Thread:Questions and Answers/@comment-71.185.74.12-20130517203447/@comment-13376834-20130518162641

How I always assumed was that after IR split into Irina and Elluka they were both adopted. Irina by the Clockworker family and Elluka by the Kriksrkenfkeng (I have no idea how to spell it) family. And Elluka just refers to Irina as her sister even though they are the same person. It's just her way of referring to her other half.