Do you have any idea how important it is to me that Duke Mahad dal Freid not only claimed Prince Chid as his son and heir despite knowing there was a 99.9% chance that Allen was Chid's biological father, but when Allen tries to confess to Millerna that Chid is likely his, the Duke _vehemently_ interjects and declares Chid is his.
Because in every way that matters, Chid IS his son. Not just his heir, not just a succesor to the throne, not just his wife's child, none of those tropes at work. Chid is HIS. SON.
Chid has been told all his life about the honourable, brave Knight of Caeli, and greatly admires the Allen of his stories. Kid's a goddamn miniature clone. It is undeniable that Marlene loved Allen, and wanted Chid to know about the man she loved, the biological father of her only child.
But Mahad is the one who helped raise Chid. Mahad is likely the one who taught him about the duchy, the allied kingdoms, policy, diplomacy. But so too is Mahad the one who Chid would have shared his dinners with, would have been by Marlene's side (as she did come to love him, as he loved her) through Chid's first steps, his first words, learning to laugh, to read, to write, to hear stories of Atlantis.
Chid may admire the Knight, but he loved his REAL father.