Iirc from the spoiler the ardal 30 years ago was his mother., so what happened might be, that house bagot ( his family that persillion killed) faked their child as an ardal and became empress even with the lies., now for whatever reason if the emperor was aware or not, they made him and persillion's mother meet and do the deed, so a royal blood and ardal blood would actually be produced, which is currently persillion
Iirc from the spoiler the ardal 30 years ago was his mother., so what happened might be, that house bagot ( his family that persillion killed) faked their child as an ardal and became empress even with the lies., now for whatever reason if the emperor was aware or not, they made him and persillion's mother meet and do the deed, so a royal blood and ardal blood would actually be produced, which is currently persillion